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Gas sensor, as one of the most important devices to detect noxious gases, provides a vital way to monitor the concentration and environmental information of gas in order to guarantee the safety of production.

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A photoelectric device that transforms observed light energy (photons) to electrical energy (electrons) is referred to as a light sensor.
Photodiodes, photoresistors, phototransistors, and photovoltaic light sensors are all typical kinds of light sensors. These components may be utilised in a variety of applications, including mobile device light detection, automated outdoor lighting, proximity sensors, and renewable energy.
Different types of light sensors can be used to measure illuminance, respond to changes in the amount of light received, or convert light to electricity.

Sources:
https://www.seeedstudio.com/blog/2020/01/08/what-is-a-light-sensor-types-uses-arduino-guide/

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A light sensor is a photoelectric device that converts light energy (photons) detected to electrical energy (electrons). Seems simple? There is more to a light sensor then just its definition. It comes in different types, used in various applications and more! Hence, in today's light sensor guide, we'll be exploring all you need to know about light sensors:

What are the types of light sensor

What is a light sensor used for

List of light sensors available at Seeed

How to use a light sensor with Arduino

Glossary of terms

Before we start with today's' light sensor guide, we'll have to understand the following terms that are commonly associated with light. I've simplified it for easier understanding:

Candela

Originated from the term candles, candela refers to luminous intensity; how strong is the light to a naked eye

The higher the luminous intensity, the higher the sensitivity it is to our eyes

Lumen

Measures the total amount of visible light from a light source through the relationship between luminous intensity and the angle that a light beam fills

Commonly used to rate the brightness of a lightbulb

To simply put it Lumen = Total amount of light emitted in all directions

Lux

Used to measure illuminance, the area where the luminous flux is spread

It's similar to Lumen but it takes into account the surface area

To simply put it, Lux = total amount of light that falls on a parrticular surface

If you're still confused between Lumen and Lux, here's a graphical representation:

Lux vs Lumen

Understood the terms? Let's now get started!
What are the types of light sensor

There are different types of light sensors available; mainly Photoresistor, Photodiodes, and Phototransistors. Sounds technical? I'll break it down with the explanations below!

1. Photoresistors (LDR)

The most common light sensor type that's used in a light sensor circuit are photoresistors, also known as a light-dependent resistor (LDR). Photoresistors are used to simply detect whether a light is on or off and compare relative light levels throughout a day.

What are photoresistors made of?

A high resistance Semiconductor material called cadmium sulfide cells, highly sensitive to visible and near-infrared light

How photoresistors work?

As its name suggests, photoresistors work similarly to your regular resistors, but instead resistance change is dependent on the amount of light it's exposed to.

High intensity of light causes a lower resistance between the cadmium sulfide cell

The low intensity of light results in a higher resistance between the cadmium sulfide cells

This working principle can be seen in applications such as street lamps, wherein the day, the higher light intensity results in lower resistance and no light produced.

2. Photodiodes

Photodiodes are another type of light sensor. But instead of using the change in resistance like LDR, it's more complex to light, easily changing light into a flow of electric currents.

Also known as a photodetector, photo sensor

What are photodiodes made of?

Photodiodes are mainly made from silicon and germanium materials and comprise of optical filters, built-in lenses and surface areas

How photodiodes work?

Photodiodes work on the working principle called the inner photoelectric effect. To simply put it, when a beam of light hits, electrons are loosened, causing electron-holes which results in electrical current to flow through.

The brighter the light present, the stronger the electrical current will be

Photodiode light sensor applications

Since current generated by photodiodes are directly proportional to the intensity of light, it makes it favorable for light sensing that requires fast light response changes.

Since photodiodes are responsive to infrared light, it's applicable for more usages as well.

Here are some of the applications of photodiode:

Consumer electronics ranging from compact disc players to smoke detectors and even remote control devices

Medical applications such as equipment/instruments used for measuring and analysis purposes

Solar energy systems such as solar panels

3. Phototransistors

The last light sensor type we'll be exploring today is the phototransistor. The phototransistor light sensor can be described as a photodiode + amplifier. With the added amplification, light sensitivity is far better on the phototransistors.

However, it doesn't fair better in low light level detection as compared to photodiodes.

Since both light sensor types share a similar working principle, do refer to the previous explanation!

What is a light sensor used for? Applications

Despite the different types of light sensors, it can still be used in a variety of applications as seen below:

Consumer electronics

Ever wonder what's behind your smartphone and tablets that allow for auto screen brightness adjustments? Yes, it's an ambient light sensor! It measures the ambient light level of your surroundings and determines the suitable brightness of your screen!

Automobiles

Similarly to how light sensor works on your smartphones, it is used in automobiles to support the drivers' field of vision. The present light sensor detects surrounding ambient light, and if it's getting too dark, it'll automatically turn on light systems!

Agricultural Usages

We all know crops need mainly two things for growth; Sunlight and water. This is where a light sensor comes to play, helping farmers keep their crops hydrated yet not over-hydrating it. Here's how:

A light sensor is connected to a sprinkler system, detecting levels of sunlight and only activating it when the sun isn't at its brightest

It is used alongside other temperature sensors to help gather informative data as well

Security applications

Commonly used in circuits for shipment cargos, light sensors are connected to circuits and placed inside as it can detect whenever a container is open due to the change in light exposure. This helps in better processing of lost goods and tracking of personnel.

As such, photoresistors are commonly used due to its suitability

Light sensors available at Seeed

Since photoresistors, photodiodes, and phototransistors offer versatility at affordable pricing, you can collect illuminance data using Arduino or Raspberry Pi through our selection of light sensors available at Seeed!

Starting off the list of light sensors available right here at Seeed is the Grove - Light Sensor v1.2! Alongside its low price tag of $2.90, comes a highly sensitive and reliable photodiode for your light-sensing needs!

Easily parable with your Arduino board through our Grove plug and play system, you'll save yourself some trouble of connecting jumper wires and soldering it on!
Its features include:

Dual OpAmp chip LM358 on board

Analog module

Onboard grove port for easy interfacing

Convertable electrical signal output
Depends on the ADC on your controller board, E.g. it can output 0-255 for an 8-bit ADC)

Small form factor

Recognize wider spectrum

Need a light sensor that uses a phototransistor instead of the traditional light-dependent resistor (LDR)? This option is for you!

Packed with an LS06-S phototransistor, this light sensor module has much more linear analog output conforming to illuminance, ranging from 0 to the supplying voltage of normally 5V.
Its features include:

Linear analog output conforming to illuminance

Low dark current and low working lux

Integrated Grove port for ease of usage

Small form factor

If you're looking for a digital signal output option alongside a selectable light spectrum range, the Grove - Digital Light Sensor is the one for you!

Based on the I2C light-to-digital converter TSL2561 that does the digital signal outputting, this light sensor module features dual light-sensitive diodes, where you can switch between 3 modes to take your reading!

These three modes are infrared mode, full-spectrum, and human visible mode
The human visible mode gives you reading close to your eye feelings

Its features include:

Wide dynamic range: 0.1 - 40,000 LUX

Wide operating temperature range: -40deg to 85deg

High-resolution 16-Bit digital output at 400 kHz I2C Fast-Mode

Programmable interrupt function with User-Defined Upper and lower threshold settings

Selectable detection modes

Though it's Made for direct sunlight detection with UV, this digital light sensor is suitable for a variety of other light sources as well, including visible and infrared light.

Based on the SI1145 sensor from SiLabs, it's a low-powered, reflectance-based, infrared proximity, UV index and ambient light sensor with an I2C digital interface and programmable-event interrupt output.

Since performance is key, this light sensor offers a wide dynamic and spectrum detection range to top it all off!
Its Features Include:

Perhaps the most interesting light sensor option on this list is the Grove - Heelight Sensor! Unlike any other light sensor on this list, this only does contactless light control through voice recognition.

Based on heelight, a smart colorful bulb controlled by digital sound waves, this sensor doesn't require Bluetooth, WiFi, or ZigBee!

However, do note that this sensor only recognizes digital voice.
Its features include:

Digital voice recognition

Support for over 500 digital voice commands

Compatible with Grove system

How to use a light sensor with Arduino?

We've gone through the theoretical side of light sensors and now its time for our light sensor Arduino tutorial.

For today's tutorial, we'll be using the Grove - Light Sensor v1.2 module and an LED bar to build a simple circuit that changes based on light!

Here's what you need:

Seeeduino is Seeed's very own Arduino board, built with relative advantages over the regular

Hardware connections:

Step 1: Connect Grove - Light Sensor to port A0 of the Grove - Base Shield

Step 2: Connect Grove - LED Bar to port D2 of Grove - Base Shield
You can opt to directly connect Grove - Light Sensor to Seeeduino as well

Step 3: Plug Grove - Base Shield into Seeeduino

Step 4: Connect Seeeduino to PC through a USB cable

It should look something like this after the above steps:

Software configurations with Arduino Code

Step 1: Download the Grove-LED Bar Library from Github

Step 2: Refer to How to install library for installation of library for Seeeduino

Step 3: Copy the code below into Arduino IDE and upload it

#include <Grove_LED_Bar.h> Grove_LED_Bar bar(3, 2, 0); // Clock pin, Data pin, Orientation void setup() { // nothing to initialize bar.begin(); bar.setGreenToRed(true); } void loop() { int value = analogRead(A0); value = map(value, 0, 800, 0, 10); bar.setLevel(value); delay(100); }

The LED Bar should now change based on light

If you would like a video tutorial on the above light sensor, you may refer to this instead:

Resources and Going Further

Light Sensor projects:

Want to go further than just building a light sensor circuit with LED? Try this list of light sensor projects available on our hackster.io page!

Product Resources:

For documents on the three other light sensor recommendations, you can visit its respective product pages

Summary

That's all for today on light sensors. I hope with today's blog, you get a deeper understanding of what it is, how it works, its usages, and what it takes to build one with an Arduino!

To help you easily get started, do consider the list of touch sensor I've recommended!

Please follow and like us:

Tags: candela, electrons, Light sensor, light sensor applications, light sensor arduino, light sensor circuit, light sensor guide, light sensor list, light sensor phone, light sensor types, light sensor uses, lumen, lux, photodiodes, photons, photoresistors, phototransistors

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What is a light sensor? Types, Uses, Arduino Guide - Latest open tech from seeed studio

# data[].attributes.attachment_link.description
A light sensor is a photoelectric device that converts light energy (photons) detected to electrical energy (electrons). Seems simple? There is more to a light sensor then just its definition. It comes in different types, used in various applications and more!

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A temperature sensor is an electronic device that measures the temperature of its environment and converts input data into electronic data for recording, monitoring, or signaling temperature changes. There are various types, including contact temperature sensors that require direct contact with the object being monitored, and non-contact temperature sensors that indirectly measure the temperature of an object.

Source:
Jost, Danny. “What Is a Temperature Sensor?” Fierce Electronics, 2 July 2019, www.fierceelectronics.com/sensors/what-a-temperature-sensor. Accessed 27 July 2023.

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A colour sensor can detect the the received light intensity for for red, blue, and green, allowing the colour of the target item to be determined. The sensor is quite handy for line following as well as obstacle detection. Because the colour sensor can differentiate between colours and detect the strength of reflected light, it is suitable for line following.

sources:

https://www.keyence.co.in/ss/products/sensor/sensorbasics/color/info/#:~:text=A%20colour%20sensor%20can%20detect,colour%20of%20the%20target%20object.

https://coderz.zendesk.com/hc/en-us/articles/115003082289-The-Color-Sensor#:~:text=The%20Color%20Sensor%20is%20used,it%20ideal%20for%20line%20following.

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There are two types of colour sensors. One illuminates the object with broad wavelength light and differentiates the three types of colour in the receiver. The other type illuminates the object with the three types of light (red, blue, and green) independently.
In both scenarios, the received light intensity of red, blue and green are detected, and the ratio of light received is calculated.

If light containing the red, blue, and green wavelengths is shown on a red object, only red light will be reflected.
* The white circle in the diagram represents a white light source.

For a white object, all three colours of red, blue, and green are reflected.
* The white circle in the diagram represents a white light source.

The ratio of the red, green, and blue reflections vary according to the colour of the object.

By calculating the ratio of the intensity of the red, green, and blue light received, it is possible to distinguish differences in the colour or appearance of the object.

Differences can be detected
Left: Received light ratio 1:1:1
Right: Received light ratio 4:4:1

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What is a Colour sensor? | Sensor Basics: Introductory Guide to Sensors | KEYENCE

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Sensors come in a wide variety, and each type has strengths and weaknesses. This section provides a detailed look at colour sensors.

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Detect the presence and concentration of various hazardous gases and vapors.

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The light sensor is a passive device that converts the light energy into an electrical signal output

types of light sensors photodiodes, photoresistors, phototransistors, and photovoltaic light sensors.

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Motion sensors detect and measure movement in various electronic devices, including home and business security systems, phones, paper towel dispensers, game consoles, and virtual reality systems.

Sources:
Jost, Danny. “What Is a Motion Sensor?” Fierce Electronics, 14 Oct. 2019, www.fierceelectronics.com/sensors/what-a-motion-sensor. Accessed 27 July 2023.

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funtions-Detect fires by sensing small particles in the air using a couple of different kinds of technologies.

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Function:
The Temperature Sensor is among the most prevalent and well-liked sensors. A temperature sensor measures temperature changes by sensing the temperature, as the name suggests.
Uses: A temperature sensor can be used to help fire fighters to understand how dangerous is the situation it is as it could detect the temperature of the fire. It could also be of use at home as it could be used to detect the room temperature.
Source:
Teja, Ravi. “What Is a Sensor? Different Types of Sensors and Their Applications.” ElectronicsHub, 2 Apr. 2021, www.electronicshub.org/different-types-sensors/#:~:text=The%20simplest%20example%20of%20a,light%20it%20is%20subjected%20to. Accessed 27 July 2023.

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Color sensors are special devices that can see and recognize different colors, just like our eyes. They work by using tiny detectors that can feel and measure light. When light shines on the sensor, it tells us what color it is by giving a specific signal. These sensors are used in many things, like cameras to take colorful pictures, in factories to check if products have the right colors, and even in some gadgets we use every day.

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A pressure sensor converts the pressure to a small electrical signal that is transmitted and displayed. These are also commonly called pressure transmitters because of this. Two common signals that are used is a 4 to 20 milliamps signal and a 0 to 5 Volts signal.

https://realpars.com/pressure-sensor/#:~:text=How%20does%20Pressure%20Sensor%20Work,0%20to%205%20Volts%20signal.

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The Easiest Way to Learn Industrial Automation

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The standard units are the Pascal, Bar, and PSI or pounds per square inch.

Pressure sensors convert the pressure into an electrical signal that can be transmitted and displayed. This is why many sensors are referred to as transmitters.

These sensors commonly measure Gauge Pressure, Absolute Pressure, and Differential Pressure.

Gauge pressure is measured against the atmospheric pressure, absolute is measured against a vacuum, and the differential pressure is the difference between two pressures.

Pressure sensors are commonly used to monitor pressures in different processes.

A common thing to monitor is steam pressure. That pressure sensor can be used to control a valve to keep steam pressure at a constant level.

Another common but lesser known use is to monitor the level of a liquid in a tank.

Filter clogs are a common use of differential pressure monitoring. By knowing the pressure before and after the filter, you can determine if it is clogged.

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What is a Pressure Sensor? | Types of Pressure Sensors - RealPars

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What is a pressure sensor and how are they used in industrial applications? Learn about the types of pressure sensors in an understandable format here.

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A sound sensor is made to identify a certain sound then perform an action. They in be used in sound activating lights and other such inventions.

Project ideas

- Waiter robot, a robot that is programmed to pick a bottle of water or any liquid of your choosing by snaping your fingers.

- Snooze alarm clock, a digital alarm clock that has a voice activated snooze function. once the alarm rings, the user will be able to activate snooze by saying the command 'snooze.'

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Detecting light and converting it to an electric signal is the function of a light sensor, commonly known as a photoelectric device. Light sensors are also used to adjust the screen's brightness based on ambient light levels in consumer electronics like cellphones.

https://www.analog.com/en/design-center/glossary/light-sensor.html

https://www.seeedstudio.com/blog/2020/01/08/what-is-a-light-sensor-types-uses-arduino-guide/

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funcation- To detect nearby people or objects.

project 1- Set the faucet to turn on for a predetermined time once it detects movement.

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Function- The gas sensor detects toxic or explosive  gas form tiny particles in the air.

Project 1- Low cost leakage detector with a buzzer to detect gas leakage.

Project 2-Toxic gas detector- To detect escaped toxic gas in labs and workspaces

https://www.projectsof8051.com/lpg-gas-sensor-projects/

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Below is the list of LPG gas sensor projects from Microtronics Technologies. Engineering students are always in need of projects for their final year project submission. On this page, you will find different category projects implemented using LPG Gas sensors.

List of LPG gas Sensor Projects for engineering students

IOT Projects using LPG gas sensor

LPG Gas sensor projects videos playlist on YouTube:

In today's world, LPG is used everywhere. In our homes, hotels & restaurants, cars & buses, and industries. And then there are chances that the LPG leakage would happen. This can cause major accidents causing life threats. As we know, precaution is better than cure, so it is better to implement any system which would detect this LPG gas leakage and intimate user around it. This intimation can be in any form like a buzzer, SMS, or through an android app. That is the reason, all projects mentioned above are equally important.

You will learn Arduino Uno and GSM modem along with the LPG gas sensor in a few of these projects. Some of the above projects perform the function of an LPG gas leakage detector using Arduino. LPG gas sensor working principle is mentioned in the documentation provided with the project. We provide all documents with the project, you will get an LPG gas leakage detector project report with these projects. Also, we provide LPG gas leakage detection ppt along with the code and datasheets. And yes, the most important thing is that we do provide an mq6 gas sensor circuit diagram in this documentation section.

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LPG Gas Sensor projects from Microtronics Technologies

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List of LPG Gas Sensor projects from Microtronics. These are LPG gas leakage detector projects. You get project report, circuit diagram, ppt with LPG sensor projects.

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When an object moves within the sensor's area, it causes the sound waves to change, and the sensor detects this change, enabling it to sense motion.

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An electrical device that detects motion is a motion sensor, commonly referred to as a motion detector. As part of home security systems, motion sensors are frequently utilized to detect movement and sound an alert.
https://www.fierceelectronics.com/sensors/what-a-motion-sensor

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Color sensors are used to detect the color of different kinds of materials. The color sensor will categorize the color into one of the main primary colors, red, green blue (RGB). The senors are equipped with things to avoid/eliminate UV light and any unwanted IR light.

Source: https://www.elprocus.com/color-sensor-working-and-applications/#:~:text=What%20is%20a%20Color%20Sensor,IR%20light%20and%20UV%20light.

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ElProCus - Electronic Projects for Engineering Students

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White light is a mixture of three basic colors known as primary colors. They are red, blue and green. These colors have different wavelengths. Combinations of these colors at different proportions create different types of colors. When the white light falls on any surface, some of the wavelengths of the light are absorbed by the surface while some are reflected back based on the properties of the surface material. Colour of the material is detected when these reflected wavelengths fall on the human eye. A material reflecting wavelengths of red light appears as red. The component used to detect colors is the Color sensor.

What is a Color Sensor?

A color sensor detects the color of the material. This sensor usually detects color in RBG scale. This sensor can categorize the color as red, blue or green. These sensors are also equipped with filters to reject the unwanted IR light and UV light.

Working Principle of Color Sensor

To detect the color of material three main types of equipment are required. A light source to illuminate the material surface, a surface whose color has to be detected and the receivers which can measure the reflected wavelengths.

Colour sensors contain a white light emitter to illuminate the surface. Three filters with wavelength sensitivities at 580nm, 540nm, 450nm to measure the wavelengths of red, green and blue colors respectively.

Based on the activation of these filters, the color of the material is categorized. A light to voltage converter is also present in the sensor. The sensor responds to color by generating a voltage proportional to the detected color.

Another way of detecting color is by illuminating the material surface by Red, Blue and Green LED's one at a time. Here the sensor contains no filters but light to voltage converter. The highest amount of light reflected back by the material surface while illuminated with the red, blue and green light is calculated to detect the color.

Applications

Colour sensors are applied to measure, detect the color of the surfaces. These sensors have a wide range of applications in industrial, medical and security systems.

Some of the applications are the light color temperature measurement, RGB LED consistency control, medical diagnosis systems, health fitness systems, industrial process control, etc...

Examples

Some of the examples of color sensors available in the market are AS73211, TCS3200, TCS3400, TCS34715, TCS34727, colorPAL from parallax, SEN-11195, Lego Mindstorms EV3, etc...

Besides RGB some color sensors can also detect different colors. IR and UV radiations are to be filtered out to determine the accurate color of the material. Sensors also contain programmable light to frequency converters. These sensors are usually very thin and can be easily interfaced with a microcontroller.

The color sensor is also opted by students for cool projects using microcontrollers like Arduino. For which of your application was color sensor useful? What are the challenges you faced while using the color sensor?

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Color sensor - Description, Working Principle & Applications

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THe Article GIves A Brief Description on Color Sensor. Working Principle, Applications And Examples of The Sensor Are Also Described.

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A motion sensor, also known as a motion detector, is a device that detects movement in its surroundings and responds by triggering an action or alert. Outdoor Lighting: Motion sensors can control outdoor lighting systems, activating lights only when motion is detected, which is useful for energy conservation and as a security measure.Automatic Doors: Motion sensors are commonly used in automatic sliding doors at commercial establishments, such as supermarkets, airports, and hospitals.Which may even help elderly people.

https://home.howstuffworks.com/home-improvement/household-safety/question238.htm

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There are many different ways to create a motion sensor. For example:

It is common for stores to have a beam of light crossing the room near the door, and a photosensor on the other side of the room. When a customer breaks the beam, the photosensor detects the change in the amount of light and rings a bell.

Many grocery stores have automatic door openers that use a very simple form of radar to detect when someone passes near the door. The box above the door sends out a burst of microwave radio energy and waits for the reflected energy to bounce back. When a person moves into the field of microwave energy, it changes the amount of reflected energy or the time it takes for the reflection to arrive, and the box opens the door. Since these devices use radar, they often set off radar detectors.

The same thing can be done with ultrasonic sound waves, bouncing them off a target and waiting for the echo.

All of these are active sensors. They inject energy (light, microwaves or sound) into the environment in order to detect a change of some sort.

The "motion sensing" feature on most lights (and security systems) is a passive system that detects infrared energy. These sensors are therefore known as PIR (passive infrared) detectors or pyroelectric sensors. In order to make a sensor that can detect a human being, you need to make the sensor sensitive to the temperature of a human body. Humans, having a skin temperature of about 93 degrees F, radiate infrared energy with a wavelength between 9 and 10 micrometers. Therefore, the sensors are typically sensitive in the range of 8 to 12 micrometers.

The devices themselves are simple electronic components not unlike a photosensor. The infrared light bumps electrons off a substrate, and these electrons can be detected and amplified into a signal.

You have probably noticed that your light is sensitive to motion, but not to a person who is standing still. That's because the electronics package attached to the sensor is looking for a fairly rapid change in the amount of infrared energy it is seeing. When a person walks by, the amount of infrared energy in the field of view changes rapidly and is easily detected. You do not want the sensor detecting slower changes, like the sidewalk cooling off at night.

Your motion sensing light has a wide field of view because of the lens covering the sensor. Infrared energy is a form of light, so you can focus and bend it with plastic lenses. But it's not like there is a 2-D array of sensors in there. There is a single (or sometimes two) sensors inside looking for changes in infrared energy.

If you have a burglar alarm with motion sensors, you may have noticed that the motion sensors cannot "see" you when you are outside looking through a window. That is because glass is not very transparent to infrared energy. This, by the way, is the basis of a greenhouse. Light passes through the glass into the greenhouse and heats things up inside the greenhouse. The glass is then opaque to the infrared energy these heated things are emitting, so the heat is trapped inside the greenhouse. It makes sense that a motion detector sensitive to infrared energy cannot see through glass windows.

See the next page for more information.

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How do motion sensing lights and burglar alarms work?

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­T­here are many different ways to create a motion sensor. For example: It is common for stores to have a beam of light crossing the room near the door, and a photosensor on the other side of the ­room. When a customer breaks the beam, the photosensor detects the change in the amount of light and rings a bell.

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Functions-
A color sensor detects the main primary colors. It detects the colors using something called as a "Photo diode". color sensors can also distinguish hidden markings.
https://www.rohm.com/electronics-basics/sensor/color-sensor#:~:text=What%20is%20a%20color%20sensor,ambient%20light%20using%20a%20photodiode.

Project 1- You can use a color sensor for color blindness ( whom cannot recognize red and green light)
https://www.instructables.com/Arduino-Color-Sensor-for-Color-Blindness/

Project 2- You can make a regular color sensor for children with disabilities . ( so they can recognize colors )

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Introduction: Color Sensor for Color Blindness / Arduino Projects

This tutorial will be introducing the Color Sensor for Color Blindness (targeting red-green blindness). The main function of the project is TCS3200 Arduino Color Sensor; however, we advanced it into a new level that could help color blindness in their daily life. Because they are not able to recognize red and green, so this project is designed to determine the color by sensing the color for them, presenting it on the LCD monitor, and playing a short but identical rhythm for them to identify the color.

To make the process more interesting, this tutorial will also be showing you how I make the self-decorated box that may give you some idea for decoration!!

Hope you enjoy it!

Step 1: PREPARATION FOR OUTPUT

Installation for Arduino Color Sensor, speaker and LCD Screen monitor. I combined these three items to help people with red-green color blindness to identify colors they can't recognize. Moreover, to make the project more interesting, I include sound effect and screen.

THINGS YOU NEED:

Arduino LCD screen x1

Arduino color sensor TSC3200 x1

Arduino Speaker x1

Wires - Male connector x16 / Female connector x25

Breadboard x1

Resistance (for LCD Screen) w/ 4 color (red+red+purple+purple)

Color Paper (Green and Red)

Step 2: INSTALLATION

Prepare all the items you need and follow the image down below to connect all of them.

Follow the image provided above to connect all the outputs to function!

** There may be a tiny difference between the model's outputs with yours, therefore, the connection may vary. Make sure to check before start connection.

Step 3: PREPARATION FOR DECORATION (Optional)

THINGS YOU NEED:

1. Find a shoe box (SOFTER shoe boxes are more favorable because they are easier to cut and draw on)

2. Prepare a cutter knife/box cutter

3. Prepare any kinds of decorations you would want to put on the box, for example, the tutorial demonstrates the use of watercolor.

Therefore if you wish to follow the tutorial, prepare watercolor pigments and painting brushes.

Step 4: HOW TO DECORATE?

This is an OPTIONAL step that you can choose to either follow or skip, but decorating your hardware would make this project more personal and special. The video below is a tutorial video to demonstrate how I design and decorate with my box.

You can also choose to follow the steps below:
Process
1. Cut the upper layer of the box by measuring the exact size to fit LCD Screen monitor, Speaker, and Color Sensor; in other words, these three items will be showing and identifiable to the users after finishing, therefore do not hide them inside the box

2. Start decorating! In case you are following the tutorial, points below provide you with some tips for painting watercolor on the box.

Step 5: TIPS FOR THE DECORATION

1. Don't use too much water (the box would turn mushy); Don't use too much pigment (the box would be too heavy and thus easily break).

2. For time management, prepare dryer to dry your paint faster.

3. Have an idea before start painting.

4. Have fun!

5. Combine your Arduino with the box. Be careful to no damage either one when combining. Make any modification if needed.

Step 6: CODE

STEPS

1. Download Arduino Leonardo (or UNO)

2. Set up a frequency-scaling (varies in a different environment, must check before transferring the code to your output).

After defining all the pins to which the sensor is connected, define a variable for reading the frequency for both green and red.

Run the Serial Monitor, you will start getting some values which represent each color under your environment. (view the 2nd photo) (p.s. the variable for green will be larger than red)

Record down the code for later coding. (view 3rd and 4th photo to make modify at the highlighted part). For example, the variables for red and green is 50 and 110, therefore the when the variable shows below 50, then it will reflect as RED on the monitor; when the color sensor sense 110, then it will recognize as GREEN and show it on the monitor.

3. Copy the code and modify it by entering the early recorded values for both colors red and green. Code Link- https://create.arduino.cc/editor/kaokaokaokao/6385...

4. Send the code to your output Test to see if your project works or not.

5. If you have any question, feel free to comment down below.

Step 7: DONE!

Check out the video to see if your project has a similar function!

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Color Sensor for Color Blindness / Arduino Projects

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Color Sensor for Color Blindness / Arduino Projects: This tutorial will be introducing the Color Sensor for Color Blindness (targeting red-green blindness). The main function of the project is TCS3200 Arduino Color Sensor; however, we advanced it into a new level that could help color blindness in the...

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Temperature sensors are  gadgets that can tell if something is hot or cold. When they sense the temperature, they change it into an electric signal. We find these sensors in things we use every day, like water heaters at home, thermometers to check our temperature, refrigerators to keep our food fresh, and microwaves to cook our meals just right. They help us stay comfortable and make our stuff work better .

“Temperature Sensors: Types, Uses, Benefits, Design.” Iqsdirectory.com, 2023, www.iqsdirectory.com/articles/thermocouple/temperature-sensors.html#:~:text=What%20are%20Temperature%20Sensors%3F,thermometers%2C%20refrigerators%2C%20or%20microwaves. Accessed 26 July 2023.

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Function: Touch sensors work like a switch. When the sensor is  touched  it acts as a closed switch and when the force disappears it acts as a switch that is on.
Uses: Touch sensors can be and are a type of replacement for a switch it requires less energy and is more detectable making it more efficient. They can also be used for games that use physical object like a contoller.
Source:
Agarwal, Tarun. “Touch Sensor - Working Principle and Applications.” ElProCus - Electronic Projects for Engineering Students, 13 Aug. 2019, www.elprocus.com/touch-sensor-working-and-its-appplications/#:~:text=Touch%20sensors%20work%20similar%20to,with%20an%20insulator%20between%20them. Accessed 26 July 2023.

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uses capacitance to measure dielectric permittivity of the surrounding medium. In soil, dielectric permittivity is a function of the water content. The sensor c

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Sriven

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The ultrasonic sensor is a type of sensor that releases a certain type of sound waves that are inaudible to the human ear, these sound waves bounce back when they come in contact with an object and measure the distance and the size of the object.

project idea

We can make a device to help blind people from hitting objects or walls. First, the ultrasonic sensor detect a wall or an object, than a speaker will state the distance and size of the object so the blind person and hear it and move away from it.

https://maxbotix.com/blogs/blog/how-ultrasonic-sensors-work#:~:text=Ultrasonic%20sensors%20work%20by%20sending,and%20to%20receive%20the%20echo.

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Ultrasonic sensing is one of the best ways to sense proximity and detect levels with high reliability.

Our technical support gets emails all of the time about how our sensors work and what environments our sensors work (or don't work) in.

This guide was created as an introduction to ultrasonic sensing, its principles, and how ultrasonic sensors work in your applications.

At a top level, you need to know what an ultrasonic sensor is.

An ultrasonic sensor is an instrument that measures the distance to an object using ultrasonic sound waves.

An ultrasonic sensor uses a transducer to send and receive ultrasonic pulses that relay back information about an object's proximity.

High-frequency sound waves reflect from boundaries to produce distinct echo patterns.

Ultrasonic sensors work by sending out a sound wave at a frequency above the range of human hearing. The transducer of the sensor acts as a microphone to receive and send the ultrasonic sound. Our ultrasonic sensors, like many others, use a single transducer to send a pulse and to receive the echo. The sensor determines the distance to a target by measuring time lapses between the sending and receiving of the ultrasonic pulse.

The working principle of this module is simple. It sends an ultrasonic pulse out at 40kHz which travels through the air and if there is an obstacle or object, it will bounce back to the sensor. By calculating the travel time and the speed of sound, the distance can be calculated.

Ultrasonic sensors are a great solution for the detection of clear objects. For liquid level measurement, applications that use infrared sensors, for instance, struggle with this particular use case because of target translucence.

For presence detection, ultrasonic sensors detect objects regardless of the color, surface, or material (unless the material is very soft like wool, as it would absorb sound.)

To detect transparent and other items where optical technologies may fail, ultrasonic sensors are a reliable choice.

When using multiple sensors in an application, it's important to connect them in a way that will allow you to avoid issues like crosstalk or any other interference.

To prevent the disruption of the ultrasonic signals coming from your sensor, it's important to keep the face of the ultrasonic transducer clear of any obstructions.

Common obstructions include: For this particular use case, we offer our Self Cleaning sensors.

They are intended specifically for applications requiring the resistance of condensation in high moisture environments, our self-cleaning function is designed to run continuously in order for the self-cleaning feature to be active.

Note: The Self Cleaning function is not intended to clean dirt off of the transducer's surface. Its intent is to clear the transducer's face of moisture to operate normally.

1. HOOK UP CONTROLLER
We used an Arduino in this example, but you can use another controller and program of your choice.

2. INSTALL SOFTWARE
Install Arduino Sketch coding software onto your PC. This is where you type the code you want to compile and send it to the Arduino board.

3. SET UP YOUR SENSOR WITH ARDUINO
Plug your Arduino into the USB cable and into your computer. Once you upload Arduino, you can then compile and activate the code.

4. COMPILE AND RUN CODE
The code below will allow you to read distance in centimeters. Compile and run this code to obtain real-time distance measurements to the closest object. (Please note: this code is not only for Arduino and will run on most controllers)
const int anPin = 0;
long anVolt, cm;
void setup() {
Serial.begin(9600);
}
void read_sensor(){
anVolt = analogRead(anPin);
cm = anVolt/2;
}
void print_range(){
Serial.print("Range = ");
Serial.print(cm);
Serial.print(" cm ");
Serial.print('\n');
}
void loop() {
read_sensor();
print_range();
delay(100);
}
Ultrasound is reliable in any lighting environment and can be used inside or outside. Ultrasonic sensors can handle collision avoidance for a robot, and being moved often, as long as it isn't too fast.

Ultrasonics are so widely used, they can be reliably implemented in grain bin sensing applications, water level sensing, drone applications, and sensing cars at your local drive-thru restaurant or bank.

Ultrasonic rangefinders are commonly used as devices to detect a collision.

Ultrasonic Sensors are best used in the non-contact detection of:

Non-contact sensors are also referred to as proximity sensors.

Ultrasonic Sensors work independently of:

Light

Smoke

Dust

Color

Material (except for soft surfaces, i.e. wool, because the surface absorbs the ultrasonic sound wave and doesn't reflect sound.)

Long-range detection of targets with varied surface properties.

Ultrasonic sensors are superior to infrared sensors because they aren't affected by smoke or black materials, however, soft materials which don't reflect the sonar (ultrasonic) waves very well may cause issues. It's not a perfect system, but it's good and reliable.
Ultrasonic Distance Measuring

Distance measurement is based on the measurement of time-of-flight. The time between sending and receiving the reflected sound signal is calculated by the sensor. Ultrasonic distance sensors, like the MB7360 HRXL-MaxSonar-WR, are used as height monitors, in bin-level measurement and proximity zone detection applications.

Ex. Distance measurement would be applied in a garage parking application, sensing when a vehicle is pulled completely into a garage.

The MB7360 has been used as a bin level sensor to detect the presence or absence of grain and other materials in bins.

People Detection with Ultrasonic Sensors

Popular applications that we have worked on have been using our sensors in kiosks to detect the presence of a person approaching and detecting the presence of people in an environment, like an art installation.

One detailed use case is this interactive art installation covered in detail on Makezine.com.

We've written an article that covers key questions and concerns about the use of our sensors in these types of solutions.

Read our article, Kiosk Sensors & People Detection, to learn:

Why people are traditionally a challenging target for an ultrasonic sensor

The target types that are ideal

The benefits of an ultrasonic proximity sensor

Our goal is to help you find a sensor that is just sensitive enough for your project but avoids potential issues like picking up interference from an outside noise source.

Take a look at the following video. nuMedia Innovations developed a solution for a Microsoft Store in Seattle WA to detect human presence on a store display.

Ultrasonic Level Sensors

Tank level measurement, Fuel gauging, irrigation control.

This project for a Low Power Water Level Sensor, from Hackster.io developer Amedee, uses a weather resistant sensor from our WR line. In combination with a LoraWan node and The Things IoT open source network, this project was developed to measure the water level in a rainwater tank. Although, it can be used in many applications.

Choosing a Level Sensor
You can read this article How to Choose an Ultrasonic Tank Level Sensor which details steps you can take to choose the right sensor for your level sensing application.

We cover:

The important factors to consider when mounting your sensor

How to handle using the sensor in an environment with harsh chemicals

Which sensor lines work best for environments where frost on the sensor might be an issue

Using the sensor in harsh environments
If you're using the sensor in a harsh environment, we suggest the added protection in order for you to successfully use the sensor in your project.

As a brief guide to inform you of the compatibility of our sensors in a few environments, we've created the Chemical Compatibility Chart.

A few of the most popular chemical and environment queries are covered here.

Ordering a Fully Sealed Sensor

When you use a sensor from our WR line, the sensor pinout is left exposed, allowing you to attach wires and equipment to the sensor.

The reason we leave it open is that it provides you more flexibility in how you choose to connect to the sensors.

In some applications, it can leave the sensor exposed to the weather.

If your mounting requires you to protect the back of the sensor from damage, you must seal the sensor pinout.

For this, we offer our wire attach option as a solution...

The wire attach option will fully cover the sensor pinout by adding a small cap filled with an epoxy mixture and attached cable.

By adding the additional potting on the back of the sensor, it will seal it against the effects of weather, dust, and water...

This isn't just for people that just want to protect their sensor, it's for people with limited soldering experience.

If you don't want to risk your new sensor with the first attempt soldering it, we highly suggest working with our professional, in-house soldered sensors with wire attachments.

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Ultrasonic sensing is one of the best ways to sense proximity and detect levels with high reliability. Our technical support gets emails all of the time about how our sensors work and what environments our sensors work (or don't work) in.

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 Aleena Khadri Touch Sensor - A touch sensor is also known as a tactile sensor or touch-sensitive sensor which is an electronic device that detects physical touch or pressure applied to its surface.Touch-Based Alarms: Touch sensors can serve as part of a security system, where entering a specific touch pattern could arm or disarm the alarm.

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 Aleena Khadri Touch Sensor - A touch sensor is also known as a tactile sensor or touch-sensitive sensor which is an electronic device that detects physical touch or pressure applied to its surface.Touch-Based Alarms: Touch sensors can serve as part of a security system, where entering a specific touch pattern could arm or disarm the alarm.

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https://www.electroschematics.com/touch-alarm/

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Touch the sensor of the alarm with your finger and it starts beeping, goes on for some time and then stops. Touching it again, and it goes again! This little and flexible circuit consists of a touch sensor and a directly coupled transistor amplifier with a small loudspeaker as the output load. Two sensor strips of metal are mounted side by side on a 1×1 cm size micasheet and connected to the input of the circuit.

How the touch alarm works
Under normal conditions no current flows through switching transistors T1 and T2 and the potential across capacitor C1 is almost 0V. If the two touch plates are touched together by a finger, the alarm circuit is enabled by T1 and T2. Transistors T3and T4 form a complimentary pair amplifier, with positive feedback (regeneration) provided to the base of first transistor T3 via R3 and C2.

The sound generator oscillates at a frequency determined by C2 and R3 and the bias voltage of T3. The bias voltage of T3 can be changed by changing the values of R2 (and R1). The alarm will provide quite loud audio output into an 8 Ohm speaker with a 9V battery at a current drain of less than 100mA. Needless to say, this is an ultra simple hobby circuit. You can experiment with different component values (R1,R2,C1,C2,R3 and R4, etc) to make your own special alarm!

Touch Alarm Circuit Schematic

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Simple Touch Alarm Circuit - ElectroSchematics.com

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Touch the sensor of the alarm with your finger and it starts beeping, goes on for some time and then stops. Touching it again, and it goes again! This

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Touch sensors are small low cost gadgets that are used to detect physical touch. Touch sensors can be found in touch screen devices, lamps, and robots. Touch sensors have replaced things such as switches and buttons. Touch sensors can be found in lots of things, for example iphones.

Link - https://www.seeedstudio.com/blog/2019/12/31/what-is-touch-sensor-and-how-to-use-it-with-arduino/

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Touch sensor has been common nowadays for displays and IoT projects with Arduino. They can be found in lamps, touch screens of smartphones, and other wide arrays of applications as well. However, do you understand the working principle of a touch sensor and how to use it alongside your Arduino?

Well, in this touch sensor guide, I'll be covering the following to help you better understand Arduino and touch sensor by covering:

What is a touch sensor

How does a touch sensor work

Touch sensor applications

Types of touch sensor

List of touch sensor recommendations

How to use touch sensor with Arduino

As this guide may be exhaustive, simply press CTRL + F on your keyboard to search for what you're looking for!
What is a touch sensor?

Grove - Touch Sensor

A touch sensor is an electronic sensor used in detecting and recording physical touch. Also known as tactile sensors, it's a small, simple, low-cost sensor made to replace old mechanical switches we seen in the past.

How does touch sensor work?

Working principle

A touch sensor works like a switch, where when there's contact, touch, or pressure on the surface of a touch sensor, it opens up an electrical circuit and allows currents to flow through it.

What is touch sensor used for? Key Applications

As mentioned in my introduction, a touch sensor is used for a wide array of applications, with those being:

Touch sensor in robotics; a touch sensor is commonly used in robots, enabling basic movement and the ability to detect touch in its surroundings (E.g. When the robot runs into something, the touch sensor can have it to stop moving)

Smartphones, automotive, industrial applications

Touch sensor faucet in kitchens; allowing for control of running water without having to physically turn the knob

Most other applications that require pressure/distance measurement

Types of touch sensor

The above explanations of how a touch sensor work and its applications apply to a generic sensor, where there are still different type of touch sensor that works uniquely and is more applicable for certain applications. Hence, I'll be introducing the two main touch sensor types with its working principle/usages!

*Note: The following types of touch sensors can be referenced as touch technology too; used on touch screens to enable your device to interpret and deliver your commands.

Capacitive touch sensor

Commonly associated with MicroChip at42qt1010, a Capacitive touch sensor measures touch based on electrical disturbance from a change in capacitance. It consists of an electrode film on top of the glass panel that's conductively coated with a printed circuit pattern around the outer viewing area.

How capacitive touch sensor work:

1. The user applies touch on the glass panel

2. The printed circuit panel around the outer viewing area of the glass panel creates an electrical charge across the surface

3. It results in a decrease in capacitance and allows the system to determine the touchpoint
Multiple touchpoints can be detected as well, allowing for touch pinch and spread

Capacitive touch sensor applications:

Portable devices such as smartphones and tablets (iPhones, iPad, etc.)

Home applications such as touch lamps

Automotives

Industrial

Advantages of a capacitive touch sensor:

Doesn't require pressure to be applied since
it's built on the glass itself, hence making force insignificant to sensing requirements

Support for multi-touch

High responsiveness

Disadvantages of a capacitive touch sensor:

Vulnerable to abrasion

Reliability concerns when used in harsh environments

Doesn't work with gloves or stylus

Resistive touch sensor

Resistive touch sensor measures touch through responding to the pressure applied to their surface. It consists of two conductive layers and a non-conductive separator. Unlike the capacitive touch sensors, it's not multi-touch compatible.

How resistive touch sensor work:

1. The user applies pressure against the surface

2. The outside conductive layer is then pressed against the inner layer, resulting in voltage changes

3. The voltage changes are then compared to the starting voltage, allowing for the point at which the touch took place to be calculated

Resistive touch sensor applications:

Musical instruments, touchpads, etc.

Older music players, game consoles, etc.

Office equipment

Advantages of a resistive touch sensor:

Cost-effective and durable to be used in harsh environments

Able to be used with stylus and gloves

Less complex

Low power consumption

Disadvantages of a resistive touch sensor:

The inability for multi-touch technology unlike the capacitive touch sensors

Dependent on pressure, require more pressure to be applied for sensing to take place

Capacitive vs Resistive touch sensor

Based on what I've covered above, here's the summarised comparative table between the two main types of touch sensors; Capacitive and Resistive touch sensor!

Capacitive touch sensor

Resistive touch sensor

How it measures

Electrical disturbance from a change in capacitance

Amount of pressure applied to the surface

Multi touch

Multi touch capable

Not multi touch capable

Pressure Requirement

Does not require pressure to be applied

Require and relies on pressure to be applied

Compatibility with gloves/stylus

Doesn't work with gloves or stylus

Work with gloves or stylus

Applications

Portable devices; smartphones and tablets
Home applications
Automotives and industrial usages

Musical instruments, touchpads, etc.
Older music players, game consoles
Office equipment

Others: Infrared and surface acoustic wave (SAW) touch sensor

Though the following two touch sensors are less talked about, it's still applicable as touch screen technology. Hence, here's a brief summary of both!

Infrared touch sensor

Infrared touch sensor measures touch through whether the emitting LED beam is broken or changed when an object makes contact with it. Commonly used in kiosks or gaming applications, infrared touch sensors are long-lasting and insensitive to pressure (similar to capacitive touch sensor)

Surface acoustic wave (SAW) touch sensor

As its name suggests, the SAW touch sensor measures the disturbance of ultrasonic waves sent across the surface of a glass layer. It consists of Piezoelectric crystals attached to the glass layer on the LCD display, making such sensing possible.

Which touch sensors to buy? Recommended list at Seeed

Now that we've understood most about touch sensors, here are the various types to consider! Ranging from MPR121 to AT42QT1070, we've options for beginners and avid tinkerers! All available at Seeed and Grove compatible!

Grove system is Seeed very own initiative, mainly aimed at helping users like yourself to easily use different modules, sensors, and more through our plug and play system!

We currently already hold more than 200 Grove modules, including other sensor types for you to choose from!

Don't believe how easy pairing is made possible with Grove? Below shows a general touch sensor vs one of our Grove - Touch Sensors:

Like how simple and less messy it is? All you need is a Grove Base Shield alongside your Arduino and you're good to go!

We'll talk more about the touch sensor pairing guide later on
Now let's move on to our recommendations!

Need a simple, fast, and compact touch sensor to easily help you get started with your first touch sensing project? This is the one for you!

Based on the TTP223 touch detecter IC, it's a capacitance touch sensor, integrating the same technology used on the iPhone!

Waterproof, fast response time, and low power consumption, it can be used as an inconspicuous button, tradition button key replacement, and as a waterproofed electric product!
Here are its features:

Grove compatible interface

2.0-5.5V DC supply

response time max about 60mS at fast mode, 220mS at low power mode @VDD=3V

Low power consumption

2.0cm x 2.0cm twig module

Power indicator led

Interested to find out more on the Grove - Touch Sensor?

Need a touch sensor not only capable of capacitance and touch sensing but proximity sensing as well? This MPR121 based sensor does the job!

The Grove - 12 Key Capacitive I2C Touch Sensor contains 12 completely independent electrodes with build-in autoconfiguration, alongside our Grove port which allows you to detect all 12 electrodes signals with only that!

Multiple Grove - 12 Key Capacitive I2C Touch Sensor (MPR121) can be used in a single system as well, allowing you to build a touch system with 3 times the number of electrodes! Yes, 36 electrodes!
Here are its features:

Internal 10-bit ADC

Integrated independent autocalibration for each electrode input

Completely independent electrodes with built-in autoconfiguration

I2C interface, with IRQ Interrupt output to advise electrode status changes

Hardware configurable I2C address

12 electrodes/capacitance sensing inputs in which 8 are multifunctional for LED driving and GPIO

Autoconfiguration of charge current and charge time for each electrode input

Separate touch and release trip thresholds for each electrode, providing hysteresis and electrode independence

Interested to find out more on the Grove - 12 Key Capacitive I2C Touch Sensor V2?

We've covered an MPR121 standalone module in the previous recommendation, but do you need one that comes with touch sensor feelers can allow you to feel your finger touch or proximity for touch controlling?

This sensor does just that! It includes a Touch Sensor controller and 4 finger feelers. One can insert the connectors of feelers into the base of the Sensor controller, and start sensing the touch.
Interested to find out more on the Grove - I2C Touch Sensor?

Based on the Atmel AT42QT1070, this touch sensor delivers high touch sensing performance with low external noise due to burst modulation in a spread-spectrum fashion!

External sampling capacitors are not added as well with the QT1070 using a dual pulse method of acquisition. This allows for touch sensing with only a single pin!

Here are its specifications:

Operating Voltage: 3 ~ 5.5V

Operating Current @3.3V: 1mA

Touch Keys: 7 Keys ; key0 ,key1 ,key2 are on the Grove PCB bottom side

Communicating Protocol: I2C

I2C Address: 0x1B

Interested to find out more on the Grove - Q Touch Sensor?

Ending of the list of touch sensor recommendations is this fun and unique option that's applicable for game controller applications!

Unlike the other 4 recommendations above, the Grove - Capacitive Touch Slider Sensor contains a 5-segment slider, with each touchpad having a corresponding LED to indicate touch status.

Here are its features:

32-bit MCU Subsystem

2 Buttons and a 5-segment slider

16-MHz ARM Cortex-M0 CPU

Up to 16KB of flash with Read Accelerator

Up to 2KB of SRAM

Automatic hardware tuning (SmartSense™) over a sensor range of 5 pF to 45 pF

I2C interface

Interested to find out more on the Grove - Capacitive Touch Slider Sensor (CY8C4014LQI)?
Arduino touch sensor guide

To end today's guide to touch sensors, I'll be providing a tutorial on how to pair a touch sensor with Arduino!

Here's what you need:

Seeeduino is Seeed's very own version of Arduino, build with benefits over the regular version

Hardware configurations:

Step 1: Connect the Grove - 12 Key Capacitive I2C Touch Sensor V2 (MPR121) to the port of the Base Shield
You can directly connect the module to Seeeduino as well

Step 2: Plug Grove - Base Shield into Seeeduino

Step 3: Connect Seeeduino to PC via a USB cable

It should look something like this after the above steps:

Software configurations:

Step 1: Download the Grove touch sensor MPR121 Library from Github

Step 2: Refer to How to install library to install library for Arduino

Step 3: Restart the Arduino IDE. Open the example, you can open it by copying the following code into a new sketch in Arduino IDE

#include "Seeed_MPR121_driver.h" Mpr121 mpr121; u16 touch_status_flag[CHANNEL_NUM]={0}; void setup() { s32 ret=0; Serial.begin(115200); if(mpr121.begin()<0) { Serial.println("Can't detect device!!!!"); } else { Serial.println("mpr121 init OK!"); } delay(100); } void loop() { u16 result=0; u16 filtered_data_buf[CHANNEL_NUM]={0}; u8 baseline_buf[CHANNEL_NUM]={0}; result=mpr121.check_status_register(); mpr121.get_filtered_reg_data(&result,filtered_data_buf); for(int i=0;i<CHANNEL_NUM;i++) { if(result&(1<<i)) /*key i is pressed!!*/ { if(0==touch_status_flag[i]) { touch_status_flag[i]=1; Serial.print("key "); Serial.print(i); Serial.println("pressed"); } } else { if(1==touch_status_flag[i]) { touch_status_flag[i]=0; Serial.print("key "); Serial.print(i); Serial.println("release"); } } } delay(50); }

Step 4: Upload the demo. If you do not know how to upload the code, please check How to upload code.

Step 5. Open the Serial Monitor of Arduino IDE by click Tool-> Serial Monitor. Or tap the Ctrl+Shift+M key at the same time. Set the baud rate to 115200.

You should get the result if everything goes well. When you touch the CH0 ~ CH11 pads, it will trigger key ?pressed and key ?release

mpr121 inmpr121 init OK! key 11pressed key 11release key 10pressed key 10release key 0pressed key 0release key 2pressed key 2release

*Note: The above tutorial is for Arduino interfacing. There's a touch sensor raspberry pi guide on our wiki page as well!

Summary

That's all for today on touch sensors. I hope with today's blog, you get a deeper understanding of what it is, how it works, and what it takes to build one with an Arduino!

To help you easily get started, do consider the list of touch sensor I've recommended:

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Touch sensors: What it is, How it works, Arduino Guide - Latest Open Tech From Seeed

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Touch sensor has been common nowadays for displays and IoT projects with Arduino. They can be found in lamps, touch screens of smartphones, and other wide arrays of applications as well. However, do you understand the working principle of a touch sensor and how to use it alongside your Arduino?

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Motion Sensors are sensors which detect motion when someone or something is passing by the motion sensors and these sensors are helpful in Automobile Company and Hotel room card

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ElProCus - Electronic Projects for Engineering Students

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The first motion sensor was invented in the year 1950 by Samuel Bango named as a burglar alarm. He applied the basics of a radar to ultrasonic waves - a frequency to notice fire or robber and that which human beings cannot listen to. The Samuel motion sensor is based on the principle of "Doppler Effect". Currently, most of the motion sensors work on the principle of Samuel Bango's detector. Microwave and infrared sensors used to detect motion by the changes in the frequencies they produce. To understand the working of motion sensor, you first need to know the working of a camera. The camera uses an image sensor and the lens direct light to - when the light strikes the image sensor each pixel records how much light it's getting. That outline of light and dark areas in the pixels becomes the entire video image.

Motion sensors are applicable for security systems which are used in offices, banks, shopping malls, and also as intruder alarm at home. The existing motion detectors can stop serious accidents by detecting the persons who are closest to the sensor. We can monitor motion detectors in public places. The main part of the motion detector circuit is the dual IR reflective sensor.

What is a Motion Sensor?

A motion sensor is a device that notices moving objects, mainly people. A motion sensor is frequently incorporated as a component of a system that routinely performs a task or else alert a user of motion in a region. These sensors form a very important component of security, home control, energy efficiency, automated lighting control, and other helpful systems. The main principle of motion sensor is to sense a burglar and send an alert to your control panel, which gives an alert to your monitoring center. Motion sensors react to different situations like movement in your living room, doors, windows being unbolt or closed and also these sensors can

Activate a doorbell when someone comes close to the front door.

These sensors give you an alert whenever kids enter into some restricted areas in the home such as medicine cabinet, the basement or workout room.

Conserve energy by using this sensor lighting in empty spaces.

Types of Motion Sensors

There various kinds of motion sensors are available in the market, which has their ups and downs. They are namely PIR, Ultrasonic, Microwave, Tomographic and combined types.

Passive Infrared (PIR) Sensor

All warm blooded animals produce IR radiation. Passive infrared sensors include a thin Pyroelectric film material, that responds to IR radiation by emitting electricity. This sensor will activate burglar alarm whenever this influx of electricity takes place. These sensors are economical, don't use more energy and last forever. These sensors are commonly used in indoor alarms.

Ultrasonic Sensor

Ultrasonic sensor can be active (or) passive, where passive ones pay attention for particular sounds like metal on metal, glass breaking. These sensors are very sensitive, but they are frequently expensive and prone to fake alarms. Active ones generate ultrasonic wave (sound wave) pulses and then determine the reflection of these waves off a moving object. Animals like cats, dogs, fishes can hear this sound waves, so an active ultrasonic alarm might unsettle them.

Microwave Sensor

These sensors generate microwave pulses and then calculate their reflection off of objects, in order to know whether objects are moving or not. Microwave sensors are very sensitive, but sometimes these can be seen in nonmetallic objects which can be detected moving objects on the outside of the target range. It consumes a lot of power, so these sensors are frequently designed to cycle ON & OFF. This makes it feasible to acquire past them, if you know the cycles. Electronic guard dogs utilize microwave sensors.

Tomographic Sensor

These sensors generate radio waves and detect when those waves are troubled. They can notice through walls and objects, and are frequently placed in a way that makes a radio wave net that cover ups large areas. These sensors are expensive, so they are normally used in warehouses, storage units and also in other situations that need a commercial level of security.

Combined types of Motion Sensors

Some types of motion detectors mix some sensors in order to decrease fake alarms. But, dual sensors are only activated when both kinds sense motion. For instance, a dual microwave or PIR sensor will start out on the passive infrared sensor setting, because that consumes less energy. When the passive infrared sensor is tripped, the microwave division will turn ON; then, if the remaining sensor also tripped, the alarm will generate sound. This combined type is great for neglecting fake alarms, but tuns the possibility of missing real ones.

Thus, this is all about the different types of motion sensors which include Passive Infrared Sensor, Ultrasonic Sensor, Microwave Sensor, Tomographic Sensor and Combined types. We hope that you have got a better understanding of this concept. Furthermore, any queries regarding this concept or to implement sensor based projects, please give your valuable suggestions by commenting in the comment section below. Here is a question for you, What are the applications of motion sensors?
Photo Credits:

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Different Types of Motion Sensors And How They Work

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The different types of motion sensors mainly include Passive Infrared Sensor, Ultrasonic Sensor, Microwave Sensor, Tomographic Sensor and Combined types

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The motion sensor emits ultrasonic sound waves that bounce off objects and come back to the original emission point. This can be used in security cameras so if it detects and movement it sends a alert to the owner. It can also be used in lights so when the sensor detects motion it turns the light on when there is no motion detected it turns of.

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Staff Writer, Safety & Security

Motion detectors are essential home security system components that alert you if someone is prowling in or around your home. Though there are a few different types of motion detectors, most rely on similar technologies to detect intruders: they pick up on tiny changes-in things like temperature, vibration, or radiation-in the spaces they cover.

How do motion sensors work?

There are several types of motion sensor technology-active ultrasonic and passive infrared (PIR) are two popular options, though microwave, tomographic, and dual-technology detectors also get some market share.

An active ultrasonic motion detector emits ultrasonic sound waves that reflect off objects and bounce back to the original emission point. When a moving object disrupts the waves, the sensor triggers and completes the desired action, whether this is switching on a light or sounding an alarm.

Motion detection cameras, lights, and sensors used in home security systems generally rely on PIR sensors. These detect infrared energy, which humans and animals release as heat. If the motion sensor detects an increase in infrared energy, meaning someone has approached the sensor or walked within its range, it notifies the home security control panel and an alarm sounds.

PIR sensors can be set to ignore small changes in infrared energy, so they won't trigger an alarm if the family cat or dog walks by or if the household temperature fluctuates slightly.

Some other sensors use microwave or tomographic technologies, both of which emit waves of radiation-microwave and electromagnetic, respectively. When someone or something disrupts the radiation waves, the sensor sounds an alarm.

Dual-technology detectors are, as their name implies, sensors that rely on two different motion-detecting technologies to watch for movement. These are a bit more impervious to false alarms, as both technologies have to be tripped for the alarm to sound.

Examples of motion detectors

Several types of security devices use motion sensors:

You can use motion sensors to automatically turn on a light when someone approaches your home, sound an alarm when movement is detected in your living room, or trigger a motion sensor camera to start recording when someone enters your home.

Installing motion detectors

As motion sensors have a limited range-anywhere from 50 to 80 feet-you'll want to place several around your home, especially in areas where people frequently walk, such as hallways, staircases, living rooms, and bedrooms. As a motion sensor may have a harder time detecting someone walking directly toward it, it's better to place the device alongside a hallway where a burglar would walk parallel to it.

When deciding where to place each motion sensor, make sure they are at least 10 feet away from bright windows, radiators, and heating vents, as abrupt changes in temperature or HVAC-related airflow may trigger false alarms.

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With over eight years of experience as a content writer, Cathy has a knack for untangling complex information. Her natural curiosity and ability to empathize help Cathy offer insightful, friendly advice. She believes in empowering readers who may not feel confident about a purchase, project, or topic. Cathy earned her Bachelor of Arts degree in English from Indiana University Southeast and began her professional writing career immediately after graduation. She is a certified Safe Sleep Ambassador and has contributed to sites like Safety.com, Reviews.com, Hunker, and Thumbtack. Cathy's pride and joy is her Appaloosa "Chacos." She also likes to crochet while watching stand-up comedy specials on Netflix.

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How Does a Motion Detector Work? | SafeWise

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Motion detectors typically use passive infrared (PIR) or ultrasonic technology to detect motion, but other options are available.

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A color sensor detects material color in RBG scale, categorizing it as red, blue, or green. It uses filters to reject unwanted IR and UV light.

Two types of colour sensors: one illuminates objects with broad wavelength light, identifying three color types in the receiver, and the other independently illuminates objects with red, blue, and green light.

Sources:
WatElectronics. “Sound Sensor : Working, Types, Interfacing & Its Applications.” WatElectronics.com, 7 Oct. 2022, www.watelectronics.com/sound-sensor/. Accessed 26 July 2023.

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Touch Sensors are electronic sensors capable of detecting touch. They operate as a switch when touched.
These sensors are used in lamps, mobile touch displays, Ipods, some small home appliances etc.

source: https://www.build-electronic-circuits.com/touch-sensor-circuit/

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Aleena Khadri MYP-3C The Function of a sound sensor.

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Aleena Khadri MYP-3C The Function of a sound sensor.

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The sound sensor is known as a sound detector or microphone sensor, is an electronic device that can detect and measure sound waves in its environment.Musical Instrument Tuning: Sound sensors can be used to tune musical instruments by detecting the frequency and intensity of the sound produced by the instrument.

https://www.hindawi.com/journals/js/2021/6538185/

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With the increasing abundance of material civilization, people's pursuit of spiritual civilization is also higher and higher. Although tuning is the analysis and processing of sound signal, the string signal is also a kind of sound signal, which follows the basic law of acoustics. In the field of wireless sensor network, this paper introduces the status quo of tuning tools for stringed instruments, analyses the existing problems of tuning tools for mainstream stringed instruments, and puts forward an automatic tuning system based on wireless sensor network. The hardware design of intelligent tuning system based on wireless sensor network includes audio acquisition module, tuning control module driver circuit design and voice broadcast module, and network communication module selection analysis. The software design of intelligent tuning system based on wireless sensor network includes embedded software design and mobile software design. Embedded software design mainly includes system flow design and automatic tuning function design. In this paper, an improved endpoint detection algorithm is used to separate the chord tone from the nonchord tone, and an improved pitch detection algorithm is used to get the accurate pitch frequency of the chord tone signal. The function and performance of the tuning system are tested to verify the reliability of the optimized intelligent tuning system.

1. Introduction

Wireless sensor network (WSN) is a wireless network composed of a large number of static or mobile sensors in a self-organizing and multihop way to cooperatively perceive, collect, process, and transmit the information of the perceived object in the geographical area covered by the network and finally send the information to the network owner. Sensor network realizes three functions of data acquisition, processing, and transmission. Together with communication technology and computer technology, it constitutes the three pillars of information technology [ 1]. In order to obtain accurate information, a large number of sensor nodes are often deployed in the monitoring area, which can reach tens of thousands or even more. The large scale of sensor network includes two aspects: on the one hand, sensor nodes are distributed in a large geographical area, such as forest fire prevention and environmental monitoring using sensor network in the original large forest; a large number of sensor nodes need to be deployed; on the other hand, sensor nodes are densely deployed. A large number of sensor nodes are densely deployed in a small space. Sensor nodes have the ability of self-organization, can be configured and managed automatically, and automatically form a multihop wireless network system that forwards monitoring data through topology control mechanism and network protocol [ 2]. In sensor networks in use process, part of the sensor node failure due to run out of energy or environmental factors, there are also some node in order to make up for failure, added to improve the accuracy and the monitoring network; the nodes in sensor networks dynamically increase or decrease, so that the topology of the network will dynamically change subsequently. The self-organization of sensor network should be able to adapt to the dynamic changes of network topology.

The network reports information about a specified event to the user. This idea of using the data itself as a query or transmission cue is closer to the habit of natural language communication. Sensor network is a data-cantered network. A large number of sensor nodes are randomly deployed in or near the monitoring area and can form a network through self-organization. The data monitored by the sensor node is transmitted hop by hop along other sensor nodes. In the transmission process, the monitoring data may be processed by multiple nodes and then routed to the sink node through multiple hops and finally reached the management node through the Internet or satellite. The processing capacity, storage capacity, and communication capacity of sensor nodes are relatively weak, and they are powered by small-capacity batteries [ 3]. From the perspective of network function, in addition to local information collection and data processing, each sensor node also needs to store, manage, and fuse the data forwarded by other nodes and cooperate with other nodes to complete some specific tasks. The sink node has relatively strong processing capacity, storage capacity, and communication capacity. It is the gateway connecting sensor network and Internet external network. It realizes the conversion between the two protocols, simultaneously issues the monitoring tasks from the management nodes to the sensor nodes, and forwards the data collected by WSN to the external network. The management node is used to manage the whole wireless sensor network dynamically. The owner of the sensor network accesses the resources of the wireless sensor network through the management node. Sensor network is used to perceive the objective physical world and obtain the information of the physical world.

Tuning is the basic pitch calibration before the performance of a string instrument. Due to the instrument composition characteristics of a string instrument, the string is fixed on the instrument by a rotating shaft, and tension is exerted on the string through the rotating shaft. The vibration frequency of the string changes with the amount of tension applied, thus changing the pitch of the sound [ 4]. At present, the technology commonly used in the orchestra provides the signal of pitch by using the tuner and then adjusts the pitch by the player turning the shaft of the string according to the signal instructions. If the stage is about to perform, the tuning signal is not used, but the pitch is adjusted by player's own sense of pitch. However, the human body, after all, is not a precise machine; each player for pitch perception is also different; therefore, tend to be more of the same instruments in the orchestra will still exist errors made by pitch, because the audio is not exactly the same, physically unable to achieve constructive interference of the resonance effect, making the music of the orchestra of the division could resonate with [ 5]. How to calibrate string instruments in the whole group at the same pitch has always been an unsolved problem of existing technology. Existing technology is divided into passive and active tuning; passive tuning technology directly by the musicians with its own pitch to adjust elastic strings, or use a separate tuner with instrument itself, guided by means of led display musicians who manually adjust the strings to the appropriate firmness, actual applications to cooperate the artistic conception of music, and play effect. Many musicians will adjust the corresponding pitch; the existing active tuning tuner cannot do this; existing technology is an object with a single individual instrument to carry on the design; only in the case of the orchestra, music is responsible for rendering the music director of music only in advance before the performance will present the request message to the effect of musicians, not appropriate for fine-tuning in the process of performance.

In recent years, with the continuous improvement of material living standards, people's demand for spiritual and cultural entertainment is also growing. Musical instrument learning has become one of the prevailing spiritual and cultural entertainment activities. Among them, string instruments such as guitar and ukulele have gradually become popular instruments in China due to their advantages of being easy to use, convenient to carry, and affordable. When people use stringed instruments, tuning of stringed instruments will inevitably be involved [ 6]. Because only when the stringed instrument is in tune, it can make good music. Tuning is not an easy task for string instrument lovers without professional learning, especially beginners. Tuning of stringed instruments such as guitars and ukuleles refers to the process of constantly comparing the pitch of the strings with the target pitch and then adjusting the knob of the head to adjust the pitch to the target pitch. Initially, stringed instruments were tuned by ear, but this method was only suitable for professionals with long training and was difficult for instrument lovers and beginners. With the continuous development of science and technology and the popularity of stringed instruments, a variety of tuning tools appear on the market. At present, there are two main types of tuning tools for stringed instruments in the market, one is electronic tuner, and the other is tuning software. These tools detect the current pitch of a stringed instrument by sensing the sound it makes and then display the current pitch on the screen for user's reference. This is equivalent to the instrument lovers having a pair of sensitive ears, but the following tuning work still needs to be manually completed by the user, which will inevitably lead to a long tuning time and unsatisfactory tuning results due to human error. Although these two kinds of tuning tools can solve the tuning problem of people to a certain extent, they have single function and are applicable to limited instruments, which cannot well meet people's increasing demand for tuning devices.

Although sound and voice are both sound signals, the basic principle of recognition also has something in common, that is, the analysis of sound signals, the application of noise processing, characteristic analysis, recognition, and other processing processes. However, after in-depth research on the sound characteristics of piano, it is found that there are obvious differences between piano sound and voice. The fundamental frequency range of speech is between to, while the fundamental frequency range of piano sound is much larger than that of speech, which increases the difficulty of applying speech recognition to piano sound recognition. However, harp recognition has stronger theoretical feasibility and practical operability than speech recognition. First of all, harp recognition is only for the whole range of notes to recognize, while speech recognition is completed by the establishment of a vocabulary database; the amount of data is relatively large. Secondly, there are great individual differences in pronunciation, and the sound is also very different, so it is impossible to be completely the same. Secondly, the individual difference of pronunciation is great, and the sound also exists great difference. But the sound produced by pressing the same key on the same instrument has a great deal of acoustic similarity and very little difference. Individual differences in speech determine that there is no completely accurate physical or mathematical quantitative description of speech. The acoustic characteristics of musical sound show that a strict mathematical model can be extracted, which provides a theoretical basis for the further research of musical sound recognition technology.

Saeed et al. proposed an automatic tuner based on fuzzy control, which performs fast Fourier transform on the collected sound signal through computer to obtain the current pitch frequency of the string. Then, the frequency difference is obtained by comparing the standard frequency as the input to the fuzzy logic controller, which drives the motor to rotate and then achieves the purpose of automatic tuning [ 7]. Because of the abundant harmonic signals in the guitar string sound, Fourier transform can easily misjudge the frequency doubling as the fundamental frequency. To solve this problem, Wang et al. used cepstrum analysis to calculate the pitch frequency of the chord signal, avoiding frequency doubling errors to a certain extent and improving the accuracy of pitch detection [ 8]. Aiming at the problem that cepstrum analysis has a large amount of calculation and is not suitable for implementation in embedded system, Zhou et al. tried to detect pitch frequency by using autocorrelation algorithm and achieved good results in low frequency band [ 9]. In view of the computing capacity of the embedded system, Wang et al. optimized the autocorrelation algorithm by using the three-level clipping method, greatly reducing the calculation amount of the autocorrelation algorithm [ 10]. In order to solve the problem of inaccurate detection of autocorrelation algorithm in high frequency band, Li et al. used harmonic peak method to conduct short-time Fourier transform after terminal detection of chord signal, which improved pitch detection accuracy of chord signal in high-frequency band to a certain extent [ 11].

3. Design and Optimization of Intelligent Tuning System in Wireless Sensor Network

3.1. Layered Architecture of Wireless Sensor Networks

Wireless sensor network communication protocol generally can be divided into four layers: physical layer, data link layer, network layer, and application layer. They are mainly connected through an interlayer communication interface. The binding function is to provide data or services directly to adjacent layers. PD_SAP, MLDE_SAP, and NLDE_SAP indicate interfaces for data transmission. PLME_SAP, MLME_SAP, and NLME_SAP indicate interfaces for network management [ 12].

Wireless sensor network systems are generally self-organizing, self-discovery, energy availability, data integration, , and distributed computing capabilities. The physical layer provides the basic guarantee for wireless sensor network communication, including stable modulation, transmission, and receiving technology. The data link layer is mainly responsible for the multichannel technology of data flow and communication, data detection and shaking, media access and error control, and other functions, which provide the basic requirements for the network layer to realize path optimization, , and multipoint communication. The network layer mainly focuses on the path optimization algorithm to ensure the delay of data communication and complete part of the data fusion processing [ 13]. The application layer mainly develops various sensor network application control software, user UI interaction design, , and some debugging software tools for users.

The main purpose of the physical layer of wireless sensor network system is to provide the powerful communication hardware interface and provide the function of the other layers of the wireless sensor network hardware foundation stable and effective communication; at the same time, in order to be able to achieve low-power wireless sensor network needs, need for the physical layer provides the function of the open/close communication services. The main function of data link layer is to control media access in wireless sensor network and error control in communication process. The purpose of media access protocol is to ensure the reliability of multipoint communication in network communication. Error control ensures the integrity and reliability of data information in the process of wireless communication and ensures that information can be transmitted to the terminal node (sink node) correctly. The main purpose of network layer protocol in wireless sensor network system is path design and maintenance. Network layer protocol is one of the important factors restricting the performance of wireless sensor network [ 14]. The performance of a wireless sensor network is closely related to the network layer protocol of the wireless sensor network, and the stability, robustness, redundancy, and power consumption of the whole system are closely related to the network layer protocol. The application layer is mainly for data storage and processing, among which the difficulty of research is data compression and fusion processing. When the data transmitted by the subordinate nodes meet certain conditions, the cluster-head node will discard certain data. Only when special circumstances occur, the actual situation data need to be sent. This can greatly reduce the amount of communication data, reduce the data redundancy of the system, and make the system more stable.

3.2. Hardware Design of Intelligent Tuning System in Wireless Sensor Network

The hardware design of the system is completed on the DE10-Nano-SoC development board. The ARM+FPG architecture and rich hardware resources can well meet the requirements of the system for the embedded platform master chip [ 15]. According to the resource distribution of the development board, IP design is carried out on the field programmable gate array (FPGA) end to realize the driver control of the main hardware modules, and voice data processing is carried out on the HPS end, and communication is carried out with the mobile phone end through wireless network. The system hardware design block diagram is shown in Figure 1.

According to the function of the device in the system, the system hardware can be divided into the following four modules: audio acquisition module is composed of pickup and audio acquisition circuit board. The pickup picks up the sound in the surrounding environment and converts the sound signal into an analogy electrical signal input to the audio acquisition board. The audio acquisition circuit board converts the collected analogy signal into digital signal, which is convenient for the embedded end to further process the audio data. The tuning control module consists of stepper motor driving control board and stepper motor [ 16]. The tuning control module mainly realizes the conversion of pulse-width modulating (PWM) wave output by FPGA into the driving current that can drive the stepper motor to run smoothly, so as to drive the stepper motor to rotate according to the predetermined speed and direction, so as to drive the knob to rotate to achieve the purpose of automatic tuning. In order to better human-computer interaction experience, the voice broadcast module will issue the corresponding voice prompt at the appropriate time. In order to facilitate users to choose the functions of the tuning system and view the system status and other information, the network communication module uses Android smartphone as the remote control and display module and realizes the data interaction between the mobile terminal and the embedded terminal through network communication.

3.3. Software Design of Intelligent Tuning System for Line Sensor Network

The system software design consists of embedded software design and mobile software design. The system software design framework is shown in Figure 2.

Embedded end software design is the key of system software design, mainly to complete the rapid and accurate automatic tuning of a variety of stringed instruments. In order to achieve this function, it is necessary to realize endpoint detection, pitch detection, motor control, and network communication functions in the embedded end. Endpoint detection: since the collected sound contains not only string sound but also speech and background noise and other sounds, and the system only needs to detect the pitch of string sound, it is necessary to conduct real-time endpoint detection on the original sound signal to eliminate the interference of speech and noise [ 17, 18]. Pitch detection: the system is tuned according to the continuous feedback of the difference between the pitch of the string and the target pitch, so the system needs to detect the pitch of the string signal to get the accurate pitch of the string. Motor control: according to the system mode, if the system is in automatic tuning mode, the motor speed, direction, and turn stop are continuously controlled by feedback based on the difference between the string pitch detected and the target pitch. If the system is in automatic winding mode, the motor speed, direction, and turn stop are controlled by winding parameters set by the user on the mobile end. Network communication: in order to realize stable data interaction between embedded terminal and mobile terminal, it is necessary to select communication protocol and design data segment format. In order to facilitate users to select functions of the tuning system, view frequency, system status, and other information and practice daily rhythm, the mobile software should have tuning parameter setting, winding control, wireless communication, frequency display, and metronome functions. Tuning parameters are set to meet users' personalized tuning needs. Users can set the type of musical instrument, tuning mode, and string target pitch on the mobile terminal. The winding control is to improve the efficiency of the user changing strings. The user can remotely control the tuning module on the mobile phone to realize the automatic winding function. The above two functions are based on the data interaction between the mobile terminal and the embedded terminal, that is, the wireless communication function of the mobile terminal needs to be completed. Frequency display is to allow users to visually see the tuning frequency change and system status information. Metronome is a tool that can produce a steady beat at a variety of rates. It is mainly used to cultivate user's sense of rhythm and rhythm. In music theory, beat refers to the relationship between the length and strength of the notes organized together. The beat sign is the mark of beat, expressed by fraction, where the denominator represents what note is a beat, and the numerator represents how many beats are in each bar.

3.4. Optimized Endpoint Detection

The purpose of endpoint detection is to distinguish chord sounds from nonchord sounds. The sound signal of the system to contain string sound, speech, and background noise such as a variety of voice signal, but the system only to pitch detection of string sound signal, so if the pitch detection on the original sound signals directly, it can detect many nonstring sound pitch leading to abnormal rotation of tuning module, thus affecting the normal operation of the system. Real-time endpoint detection of the original sound signal can eliminate the interference of voice segment, noise segment, and silent segment, which can not only ensure the normal operation of the system but also improve the performance of the system. The main purpose of preprocessing is to determine the frame length. Because the sound signal collected by the system is a kind of unsteady and time-varying signal, it cannot be analysed and processed directly by digital signal processing technology which deals with steady-state signal [ 19]. However, the chord sound is formed by the excitation pulse generated by the string passing through the sound box, and the motion of the sound box is slow. Therefore, in the range of "short time," the chord sound signal can be considered to be steady and time-invariant. Therefore, before processing the collected sound signal, it is necessary to segment the signal into a stationary signal within a short time. The process of dividing a complete sound signal into many short-term stationary signals is called framing [ 20]. When the signal is divided into frames, there is usually a certain degree of overlap between two adjacent frames, which is called frame shift. This overlap is to ensure a smooth transition between frames.

3.5. Optimized Pitch Detection

Essentially is the pitch detection of music signals. Pitch, also known as pitch, is a measure by which the human ear differentiates the frequency of sound vibration. Pitch depends mainly on the frequency of the sound. Compared with speech signal, the periodicity of music signal is relatively stable. The pitch of each sound is approximately fixed, and its spectrum is approximately discrete spectrum, so it can detect the more accurate basic sound of music signal.

Because of the correspondence between pitch and frequency, the recognition in frequency domain is more straightforward, so the harmonic peak method based on fast Fourier transform appears. The signal is transformed by fast Fourier transform (FFT) to obtain a discrete peak of the frequency spectrum corresponding to the fundamental frequency or the distance from the origin of the maximum peak. Frequency resolution is essentially the frequency resolution of detection accuracy determined by sampling frequency and number of points [ 6, 21]. Consider the twelve-tone relationship, that is, the relationship between adjacent semitones and multiples. In the lower part, such as ultralow tone and difference, the frequency resolution must be accurate enough to meet the standard of piano tuning. This means that if the peak harmonic method is to be used in low frequency band, the number of points of sampling frequency must reach 1, which is bound to greatly reduce the efficiency of the whole software. Therefore, different algorithms should be used to analyse high and low frequency bands.

4. System Testing

4.1. System Overview

The embedded terminal and Android phone realize stable data interaction through network communication module. The user selects the embedded working mode through the mobile phone. The embedded end performs corresponding operations according to the parse instruction category. In the automatic tuning mode, the embedded end analyzes and processes the collected sound data in real time to get the string pitch and realizes the closed-loop adjustment of the string pitch by the tuning module according to the difference between the string pitch and the target pitch. In winding mode, the embedded end directly controls the tuning module movement according to the parameters set by the user to complete the operation of loosening or tightening the strings. In order to better human-computer interaction experience, voice broadcast module is added in the system to give users voice prompts when appropriate.

4.2. System Function Test

According to the analysis of design requirements, the system has automatic tuning function, automatic winding function, voice broadcasting function, wireless control function, and metronome function. In order to meet the diverse tuning requirements of users, the automatic tuning function of the system includes standard tuning and custom tuning. Standard tuning means that the system automatically adjusts the string pitch to standard pitch. The standard tuning function test will power on the development board, and after the system is started, use the mobile phone to establish a network connection with the embedded terminal. The tuning setting interface of the mobile terminal will select the instrument to be tuned and send the standard tuning mode to the embedded terminal. After the embedded terminal receives the data, the system status of the mobile terminal will be displayed as the standard tuning. Use the key on the embedded end to select the string number to be tuned and then connect the tuning module to the selected knob of the piano head to pluck the string. The following takes the standard tuning of guitar 2 strings as an example. When testing the standard tuning function, use the ROM electronic tuner as a reference. When the screen of the electronic tuner turns green, the tuning is complete. The test result statistics are shown in Figure 3.

4.3. System Performance Test

According to the design requirements of the system, the factors affecting the performance of the system include four aspects: false detection rate and missed detection rate of endpoint detection, pitch detection accuracy, tuning accuracy, and tuning time.

The system focuses on detecting the start and stop point of the chord signal as accurately as possible on the basis of not judging the nonchord sound as the chord sound. Use false detection rate and missed detection rate to measure the quality of endpoint detection method. Error detection rate represents the rate at which nonstring segments are judged as string segments by the endpoint detection algorithm, and is represented by . Miss rate represents the rate at which a string segment is judged to be a nonstring segment by the endpoint detection algorithm and is represented by [ 22]. The calculation formula of error detection rate and missing detection rate is where represents the number of string segments detected by the algorithm, represents the number of string segments incorrectly detected by the manually observed algorithm, and represents the number of string segments missed by the manually observed algorithm.

The system recorded a total of 50 sound signals with a duration of more than 2 minutes in the laboratory at different time periods in five days, and the strings were dialed irregularly during the recording process. Matlab was used for simulation experiments, and the experimental parameters were set the same as the system parameters. The test results of missed detection rate and false detection rate of endpoint detection are shown in Figure 4.

The test results show that the endpoint detection method adopted by the system does not produce missed detection phenomenon, but it will produce false detection phenomenon. Analysis of the cause is that some sounds are recorded in noisy conditions, leading to the method to judge the voice or noise with high energy as string sound.

The pitch frequency calculated by the system and the actual frequency, to test the pitch detection accuracy. The system selects the pitch frequency detected by the fundamental frequency analysis function provided by Praat speech analysis software as the actual frequency. The system uses Matlab to simulate the sound produced by the recorded guitar, ukulele, and bass, and its various parameters are consistent with the system parameters. Pitch detection uses harmonic peak tone method to detect pitch frequency, and the test results of treble detection accuracy are shown in Figure 5.

As can be seen from the figure, doubling error may occur before the harmonic peak method is improved, but the improved method avoids the doubling error to a certain extent and improves its detection accuracy to a certain extent.

Tuning precision refers to the proximity between the pitch frequency of the string and the target frequency after tuning. Therefore, it is necessary to use a third-party tool to detect the pitch of the instrument tuned by the system, and the difference between the current chord pitch frequency and the target frequency is the tuning precision. The system selects the pitch frequency detected by the fundamental frequency analysis function provided by Praat speech analysis software as the accurate frequency. The system adjusts the guitar and ukulele, records the sound of each string of the tuned guitar and ukulele, uses Praat voice analysis software to detect pitch and get pitch frequency, and then, calculates the tone difference between the detected pitch frequency and the target frequency, so as to test the tuning accuracy. The test data of ukulele tuning accuracy are shown in Figure 6 and Table 1. According to ukulele tuning rules, the ukulele can have seven target frequencies. Therefore, each of the seven target frequencies of the ukulele was tested 60 times. The number of times that met the requirements represented the number of times that the pitch difference between the fundamental frequency and the target frequency was within 5cent as analyzed by the Praat speech analysis software. The mean error represented the mean of the 60 test results and the pitch difference between the target frequency.

As with the ukulele tuning accuracy test. Guitars can have 21 target frequencies. Limited by the length of the paper, only 8 target frequencies are listed. Guitar tuning accuracy test is shown in Figure 7 and Table 2.

As can be seen from the figure, the average error of tuning precision of ukulele and guitar designed in this paper is within 5cent, which meets the requirements of tuning precision design index of the system.

Tuning time is the time that a string takes from the beginning of tuning to the end of tuning. The difference between the frequencies before the string is adjusted, and the target frequency will affect the tuning time, so 6 frequency differences are selected to test the tuning time of guitar, ukulele, and other instruments. Tuning time test data is shown in Figure 8.

As can be seen from the figure, the tuning time for each string of guitar and ukulele is within 10 s, which meets the requirements of the system for tuning time design indicators.

Through the function and performance test of the system, it can be seen that the human-machine interaction of the tuning system is good, and the functions of automatic tuning, winding, voice broadcasting, wireless control and display, and metronome are realized. Tuning systems currently support instruments such as guitars and ukulele. The tuning accuracy of the two instruments is within ±5 minutes, and the tuning time of each string is controlled within 10 s. In addition, the tuning system works stably and smoothly, and other functions also meet the design requirements.

5. Conclusion

In the field of wireless sensor network, this paper introduces the status quo of tuning tools for stringed instruments, analyzes the existing problems of tuning tools for mainstream stringed instruments, and puts forward an automatic tuning system based on wireless sensor network. The hardware design of intelligent tuning system based on wireless sensor network includes audio acquisition module, tuning control module driver circuit design and voice broadcast module, and network communication module selection analysis. The software design of intelligent tuning system based on wireless sensor network includes embedded software design and mobile software design. Embedded software design mainly includes system flow design and automatic tuning function design. Aiming at the problem that the traditional endpoint detection algorithm is susceptible to random noise and causes false detection, according to the characteristics of chord signal, the paper adopts the improved short-time average amplitude endpoint detection method, which improves the accuracy of chord signal endpoint detection to a certain extent. Aiming at the problem that single pitch detection method cannot meet the tuning accuracy requirement in the whole frequency band, the harmonic peak method is adopted. The function and performance of the tuning system are tested. The human-machine interaction of the tuning system is good, and the functions of automatic tuning, winding, voice broadcasting, wireless control and display, metronome are realized. Tuning systems currently support instruments such as guitars and ukulele. The tuning accuracy of the two instruments is within ±5 minutes, and the tuning time of each string is controlled within 10 s. In addition, the tuning system works stably and smoothly, and other functions also meet the design requirements. Although the system has reached the expected design requirements and performance indicators, there is still room for improving the tuning time. In the next step, more complex control algorithms can be studied to accelerate the tuning time.

Data Availability

The data used to support the findings of this study are available from the corresponding author upon request.

Conflicts of Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

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Optimization of Intelligent Tuning System for Stringed Instruments Based on Wireless Sensor Network

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With the increasing abundance of material civilization, people’s pursuit of spiritual civilization is also higher and higher. Although tuning is the analysis and processing of sound signal, the string signal is also a kind of sound signal, which follows the basic law of acoustics.

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A touch sensor works when an object get in physical contact with it. Capacities sensor technologies can be broadly divided into two main categories. Restive touch sensors respond to pressure.

https://www.elprocus.com/touch-sensor-working-and-its-appplications/#:~:text=Touch%20sensors%20work%20similar%20to,with%20an%20insulator%20between%20them.

The sound sensor has a thin piece of material called a diaphragm that vibrates when hit by sound waves. It works similar to our ears sound. The sound sensors convert the vibration into audio signal.

https://www.elprocus.com/sound-sensor-working-and-its-applications/

Motion sensors detect infrared energy which humans and animals release as heat.
Motion sensors detect changes in the level of received infrared.

https://www.safewise.com/resources/motion-sensor-guide/

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ElProCus - Electronic Projects for Engineering Students

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Touch Sensor - Working Principle and Applications

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The Article Gives a Brief Inroduction of Touch Sensor. Definition, Working Principle, Types and Applications are Explained

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A sound sensor, also known as a sound detector or sound sensor module, is an electronic component designed to detect sound waves in its surroundings and convert them into electrical signals.

The basic operation of a sound sensor involves a sensitive microphone or piezoelectric element that responds to changes in air pressure caused by sound waves.

https://www.raypcb.com/sound-sensors/#:~:text=What%20is%20a%20Sound%20Sensor,converts%20it%20to%20electric%20signals.

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Printed Circuit Board Manufacturing & PCB Assembly - RayMing

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Do you hate those long walks you have to take to switch off the lights at home while you go to bed? Well, you are not alone on that part. The good thing is that we are in an era whereby this tedious task is now easier via sound sensors. Now you can turn your lights on and off by just clapping your hands. You can play cool games in real life with your friends and do amazing things that did not seem possible a while ago via this technology. But how do sound sensors work? How can clapping your hands signal your lights to turn on or off? Well, in this article, we shall dive into these questions and try to answer them in the best possible way. We shall look at things such as:

How sound sensors work

Sound sensor Arduino

Motion sensors that use sound

How to make a sound sensor

And so much more

Sound sensors are a great wonder; when well understood, you can create pretty fascinating projects. Hence without further ado, let us help you put together the sound sensor puzzle.

Sound Sensor

What is a Sound Sensor?

We define a sound sensor as a module that detects sound waves via the sound's intensity and then converts it to electric signals.

How do Sound Sensors Work?

Sound sensors function like our ears, having a diaphragm that converts vibrations into signals. However, since the sound sensor is not human, it does not have an actual diaphragm or actual ears. A sound sensor instead consists of a peak detector, an amplifier (LM393, LM386, et cetera) that is highly sensitive to sound, and an inbuilt capacitive microphone. Sound sensors, having these components, can function correctly. They follow the following process to "hear" sound:

Sound waves are propagated through air molecules.

The sound waves are received by the inbuilt capacitive microphone

The sound waves are then amplified and digitized for the processing of sound intensity

Through this process, sound sensors can detect when you clap your hands to switch on the light or when you want to switch them off. Of course, to achieve this feat, you will have to go the extra mile but worry not because we have got you on that.

Applications of a Sound Sensor

Other than being useful alongside with Arduino to build incredible projects (we shall get into this later on), sound sensors can also be essential in so many day-to-day applications which include:

Monitoring and security systems such as door alarms, burglar alarms, et cetera.

Consumer electronics, for example, music systems, computers, and phones

Sound level recognition and ambient sound recognition

Home automation, for example, lighting your house by clapping or even whistling instead of having to manually turn off the lights via a switch

These applications are pretty fascinating and aim at making our lives easier. With the great tech advances taking place, you are bound to see this list get longer and longer as sound sensor application areas grow.

To understand the concept of a sound sensor, let us look at an interface sound sensor using Arduino.

Arduino Sound Sensor

If you are looking to add the concept of sound to your next project, then this section might help you out a lot. In this section, we shall look at:

How a sound sensor's microphone works

The sound sensor's board interface

How to merge a sound sensor onto an Arduino board

How does a Sound Sensor's Microphone Work?

Have you ever used a microphone before? If you have, you might have been puzzled about how you speak into it using a low tone, and the sound gets amplified as it gets outputted via a speaker. To know how this works, we have to get inside of a microphone, not literally, of course! But by reviewing every part of a microphone, this is because sound sensors utilize the same features, only that the sound sensor microphone is pretty tiny.

Inside a microphone, you will find a thin diaphragm that is actually one capacitor plate. You will also find another plate known as the backplate. The backplate is parallel to and close to the diaphragm. When sound waves hit the microphone, the diaphragm vibrates. The diaphragms vibration causes a change in capacitance as the plates either get farther apart or closer together. The change in capacitance causes voltage change across the two plates, which, when measured, can be useful in determining the amplitude of the sound.

Now that that is out of the way, we can now look at the sound sensor's board interface.

Sound Sensor Board Interface

A sound sensor is actually a tiny board that brings together a microphone (50Hz - 10KHz) and processing circuitry, which converts sound waves to electrical signals. A sound sensor board has three crucial parts, namely:

Electric signals are fed onto the high-precision comparator found on the sound sensor's board for digitization. The signal is then made available at the OUT pin.

To take things up a notch, you can set up a threshold using a potentiometer found on the sound sensor's board. Using this threshold, you get to learn when the amplitude of sound is HIGH (in this case, it exceeds the threshold) or when it is LOW (lower than the set threshold). Using this setup, you can set an action to be performed once on reaching a certain threshold. For example, once you clap your hands, this sound wave can cross the set threshold, which in turn will trigger the switching on of light (the action). You can play around with this setup to generate so many cool projects.

The sound sensor interface also has two LEDs, one for power and the other for status:

The power LED - lights up on powering up of the module

The status LED - it lights up when the digital output goes LOW

Sound Sensor Pinout

A sounds sensor has only three pins:

VCC pin - it supplies power to the sound sensor. It's recommended to power your sound sensor with a voltage between 3.3V and 5V.

GND - A ground connection

OUT - acts as the sounds sensor's output. It outputs high whenever conditions are quiet and LOW whenever there is detection of sound. You can connect the OUT pin to any digital pin on an Arduino board or onto a 5V relay directly or a similar device.

Connecting a Sound Sensor onto an Arduino Board

To properly utilize the sound sensors utilities, you can hook it up to an Arduino board to develop a sound sensor Arduino; let us see how this is possible.

Connecting a sound sensor onto an Arduino board is relatively simple. It would help if you started by connecting the VCC pin on the sound sensor module to 5V on an Arduino board, then connecting the GND pin to the ground. Now plug in the OUT pin to the digital pin on your Arduino, and that's it, you have mounted a sound sensor onto an Arduino.

Sound Sensor Calibration

To attain accurate readings from your sound sensor, you should calibrate it. Sound sensor modules come with a built-in potentiometer useful in calibrating the digital output (OUT).

To calibrate your sound sensor, all you have to do is adjust the potentiometer until you attain your desired threshold. Start clapping near the sound sensor's microphone as you adjust the potentiometer until you see the status LED blink responding to your clap. Remember that the set threshold determines what the digital output will output. Once you exceed the threshold, it outputs LOW. Hence the wrong calibration can mess up your entire project.

Once you have calibrated your sound sensor, you can now utilize it with no accuracy worries for your project.

How to make Sound Sensor Devices

Now that you have successfully mounted a sound sensor onto your Arduino board and you have calibrated the sound sensor, it is about time we see what this combination can do.

The following example simply detects claps or snaps then prints a message on the serial monitor; all you have to do is connect your Arduino to a computer and type in this program:

#define sensor in 7

Unsigned long lastEvent = 0; // variable that stores the time at which the last event happened

Void setup(){

PinMode(sensorPin, INPUT); // sets sensor pin as an INPUT

Serial.begin(9600);

}

Void loop(){

int sensorData = digitalRead(sensorPin); // reads the sound sensor

if (sensorData == LOW) { //if the sensor pin hits LOW, sound is ultimately detected

if (milli () - lastEvent > 25{ //if 25 milliseconds pass since the last detected sound,

//it means that the clap is detected and not because of any spurious sounds.

Serial.println("clap detected");

}

LastEvent = millis(); // remembers when the last event occurred

}

}

If everything is functioning fine, the Arduino should detect sound once you clap and display "clap detected" on the serial monitor. You can play along with this program adding in new functionalities until you develop a pretty cool project.

Troubleshooting

If you detect that the sound sensor is misbehaving, try out the following steps to fix it:

Double-check the power supply to ensure it is clean. Because sound sensors utilize an analog circuit, they are more prone to power supply noise.

The electric microphone utilized on a sound sensor is pretty sensitive to wind noise and mechanical vibration. It would be best if you hence mounted it with a resilient material. Doing so can help absorb vibrations.

The sound sensor's sensing range is pretty small, probably around 10 inches. It would be best to clap your hands or make a noise near the sensor's microphone to attain a better response.

That is how you can make a sound sensor. It is pretty straightforward, but you can use it for a lot of things that range from:

Clap switches

UV light meter

Room lights that utilize sound sensors

Adding sound wave properties to your project has never been that easy.

Now that we know how sound sensors work, let us take things up a notch by looking at some advancements made in sound sensors:

The NXT Sound Sensor

Have you ever heard of the NXT sound sensor before? Do you know how this sound sensor functions? Well, if you do not have answers to both or even one of these two questions, then this section is for you. We shall go through the NXT sound sensor and the incredible new features that it brings to the table. Hence follow along!

The NXT sound sensor is a sound sensor that comes in two different variations:

The normal sound sensor

The ultrasonic sound sensor

How does the NXT Sound Sensor Work?

The NXT sound sensor functions like a standard sound sensor mounted onto an Arduino board but with some advancements that make it unique. Due to these advancements, robots can utilize NXT sound sensors to "see" and detect objects as they move around.

The NXT sound sensor detects both DB (decibels) and DBA (adjusted decibel).

Decibel - We measuresound pressure in decibels.

DBA - in detecting DBA, the sensor's sensitivity is adapted to the human ear's sensitivity. These are sounds that you can hear via your ears in simpler terms.

DB - detects unadjusted (standard) decibels; this means that this sensor can detect sounds that are too low or too high for the human ear to hear.

The NXT sound sensor can detect and measure sound pressure levels of up to 90DB - that is almost equal to the sound pressure of a lawnmower. Sound pressure levels can be extremely complicated. Hence most NXT sound sensors display reading in percentages. The higher the percentage, the higher the sound being detected. For example:

4% to 5% is like a quiet living room

5% to 10% is like a person speaking from a distance

10% to 30% is like the noise generated when you are conversing with a person at close range

30% - 100% is like the noise produced by people shouting or when you are playing loud music

The Ultrasonic Sensor

Robots utilize the ultrasonic sensor for "vision" and detection; using this sound sensor, robots can sense and measure distance, detect movement and avoid obstacles. But how can sound sensors help in all this? Well, that all lies in the mystery known as the ultrasonic sensor.

Ultrasonic sensors utilize the same scientific principle that bats use. It produces a sound wave and then measures the time taken to hit an obstacle and then bounce back, the same way you hear an echo, only that the sound wave they produce is not as loud. Huge obstacles having a hard surface return the best reading. Curved obstacles (like a ball) made of soft fabric, or small in size are pretty hard to read for the sound sensor.

You should also note that two or more ultrasonic sensors working in the same room tend to interrupt each other.

Phasmophobia

Games are a major branch of tech. I mean, in the 21 st century, almost every handset gadget comes with a game pre-installed. What's more, games are evolving whereby we now have virtual reality games that you can play and experience everything as if you were literally in the game console yourself. Others utilize infrared, sound, and motion sensors to create a gaming environment out of your normal house. One of these incredible games the phasmophobia.

Phasmophobia is a horror game that utilizes sensors to detect a "ghost" in a room designated for the game. These set sensors are unlocked once you hit level seven through level eight. Once unlocked, you can utilize these sensors to record readings from the ghost. For the sensors to work, you have to place them on walls. Once you have perfectly placed the sound and the motion sensors, you can move back to your truck and monitor them.

Phasmophobia Sound Sensor

People use sound sensors to detect any movement that might occur in any of the designated rooms. To use the sound sensor, equip it onto your hand and then stand near a wall; you will see a hologram. Choose the most appropriate place to mount your sound sensor and you are good to go.

A sound sensor will detect any movement activity in the entire room. To visualize the radius of your sound sensor, head on to your truck and check on the map where you mounted the sound sensor. The sound sensor's radius will be displayed in yellow giving a clear visual of the radius.

Remember that the sound sensors, once mounted on a wall, picks up any movement that occurs in the room. Therefore, if any of your teammates wander into a room, the sound detector will sense them and produce a false alarm. When the sound sensor picks up sound, it displays an alert on the gaming monitor. The room that has the sound sensor will also be displayed on the monitor.

When used with infrared and motion sensors, sound sensors give phasmophobia a great touch that makes the game super thrilling. Now that is what we call taking things up a notch.

Phasmophobia Motion Sensors

Phasmophobia motion sensors function exactly like sound sensors but have a pretty small radius. Therefore the best place to mount your motion sensor would be in an alley. Alleys have a straight line detection range, making motion detection pretty easy.

When a motion detector senses motion, it displays an alert on the map's screen in the truck. Motion sensors cannot differentiate between a teammate and a ghost too.

Now that we are in the motion sensor section let us look at motion sensors with sound.

Motion Sensors with Sound

Motion sensors are important for a lot of things:

In playing games such as phasmophobia

To control devices via motion detection

For security purposes - this is the core use of motion detectors

How do Motion Sensors with Sound help as per Security?

If anyone comes into your house while you are away, you will want to know about it since they might be thieves. Well, motion sensors with sound will alert you immediately they sense movement in your house while you are away. To avoid false alarms, you have to activate these motion sensors when you want to use them and deactivate them when you don't.

How do Motion Sensors with Sound Function?

Motion sensors with sound work pretty much like sound detectors. See, when you are moving around, you send out vibrations. A motion detector picks these vibrations via a diaphragm, just like the sound sensor's, and then wave conversion occurs. While playing a game such as phasmophobia, the instance anything or anyone sends out a vibration (might be vibrations from footsteps), the motion sensor with sound picks up this vibration and produces a reading.

Ultrasonic Motion Sensors

An ultrasonic motion sensor is another motion sensor that utilizes sound to detect motion. Ultrasonic motion sensors utilize the same principle that is used by microwave sensors. However, ultrasonic motion sensors use sound waves instead of bouncing off microwaves on obstacles. By bouncing off sound waves on surfaces, these motion sensors can detect motion and produce readings.

Sound Sensor Projects

Before we wrap things up, let us leave you with some sound sensor projects that you can try out on your own to test the knowledge that you have gained from this article:

Using a sound sensor, you can develop a device that can sense overall sound and air quality. In doing so, you can help reduce sound pollution in your area.

You know how babies can cry for hours and hours when no one is around. That can be a problem, but one that can be solved using a sound sensor. A baby monitor that utilizes sound sensors can pick up noise and alert you when the baby starts to cry. You can add more features, such as a camera, to increase the monitor's efficiency.

Dogs tend to sometimes misbehave when left home alone. However, using a dog barking tracker, you can easily track your dog's barking to know what your dog is up to. Of course, you will have to first track the dog's barking pattern, but after that, you are good to go.

These are but a few of the many projects you can develop using a sound sensor.

Conclusion

A sound sensor is a crucial device that can do wonders in the tech industry. Its applications are endless, and benefits seem to go up every day. We hope this article has answered all the questions you might have heard regarding sound sensors and their application.

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All You Need to Know About Sound Sensors - Printed Circuit Board Manufacturing & PCB Assembly - RayMing

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Do you hate those long walks you have to take to switch off the lights at home while you go to bed? Well, you are not alone on that part. The good thing is that we are in an era whereby this tedious task is now easier via sound sensors.

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Function: The photoelectric effect is how light detectors function. Light has the ability to behave as a photon, a type of particle. The energy of the light is absorbed by the electrons when a photon strikes the metal surface of the light sensor, boosting their kinetic energy and enabling them to be expelled from the substance.

2 ways to use light sensors: The Arduino-managed high-sensitive LDR-based power saver for street light control systems, a solar highway lighting system with auto turn-off in the daytime, and other practical embedded systems-based sensor-based projects can all be designed using the light sensor circuit.

Source: https://www.watelectronics.com/light-sensor-circuit-working-operation/#:~:text=The%20light%20sensor%20circuit%20can,auto%20turn%20off%20in%20daytime%2C

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The controlling of street lights, make a light sensor circuit outdoor lights, a few indoor home appliances, and so on are usually maintained and operated manually on several occasions. This is not only risky but also results in wastage of power with the negligence of personnel or unusual circumstances in controlling these electrical appliances on and off. Hence, (based on the requirement) we can utilize the light sensor circuit for automatic switching of the loads based on daylight's intensity by using a light sensor. In this article, we discuss in brief about how to make a light sensor circuit and its working operation.

What is Sensor?

Before going to learn about the light sensor, primarily, we must know what is sensor. Sensor is a device that is used to detect the changes in quantities or events and appropriately produce the outputs.

There are different types of sensors such as light sensors, temperature sensor, humidity sensor, pressure sensor, fire sensor, ultrasonic sensors, IR sensor, touch sensor, and so on.

What is a Light Sensor Circuit?

The light sensor circuit is a simple electrical circuit, which can be used to control the (switch on and off) electrical load appliances like lights, fans, coolers, air conditioners, street lights, etc., automatically. By using this light sensor circuit, we can eliminate manual switching as the loads can be controlled automatically based on the daylight intensity. Hence, we can describe it as an automatic light sensor.

The light sensor circuit helps to evade the manual control of the street lights erected on highways which is risky and also causes wastage of power. The light sensor circuit consists of major electrical and electronic components such as light sensor, Darlington pair, and relay. To understand the working operation of the light sensor circuit, we must know a brief about the components used in designing the light sensor circuit.

Light Sensor

There are different types of light sensors available such as photoresistors, photodiodes, photovoltaic cells, phototubes, photomultiplier tubes, phototransistors, charge coupled devices, and so on. But, LDR (Light Dependent Resistor or photoresistor) is used as a light sensor in this light sensor circuit. These LDR sensors are passive and doesn't produce any electrical energy.

But, the resistance of the LDR changes with the change in the (light illuminated on the LDR) daylight intensity. LDR sensor is rugged in nature, hence can be used even in dirty and rough external environments. Hence, LDR is preferable compared to other light sensors as it can be used even in the outdoor lighting of homes and in automatic street lights as well.

Light Dependent Resistor is a variable resistor that is controlled by light intensity. LDRs are made of high resistance semiconductor material, Cadmium Sulphide that exhibits photoconductivity.

During night time (when the light illuminated on LDR decreases), the LDR exhibits a very high resistance of around a few MΩ (Mega Ohms). During daytime, (when the light is illuminated on LDR), resistance of LDR decreases to around a few 100Ω (hundred Ohms). Hence, the resistance of LDR is inversely proportional to the light illuminated on LDR.

As shown in the above figure, the LDR consists of two terminals similar to a general resistor and a wave-shaped design on its top surface. The graph shown above represents the inverse proportionality of the LDR with the light intensity.

The major drawback of the LDR is that, it is sensitive to light illuminated on it irrespective of the nature of light (natural daylight or even artificial light).

Darlington Pair

The back-to-back connection of two transistors is called as a Darlington pair, this Darlington pair transistor connection is used in this light sensor circuit.

This Darlington pair transistor is also considered as a single transistor that has very high current gain compared to the general transistor gain. The product of input current and gain of the transistor gives the input given to the load through the Darlington pair. We know that, if the base voltage must be greater than 0.7v, then the transistor switches on - but, in case of Darlington pair, the base voltage must be 1.4v as the two transistors are required to be switched on.

Relay

A relay plays a vital role in the light sensor circuit for activating the load or for connecting the load to the light sensor circuit as well as to the AC mains.

Generally, the relay consists of a coil, this coil gets energized whenever it gets enough supply (required amount of supply depends on the rating of the relay).

Light Sensor Circuit Working Operation

The light sensor circuit is an electronic circuit designed using (light sensor) LDR, Darlington pair, relay, diode, and resistors which are connected as shown in the light sensor circuit diagram. A 230v AC supply is provided to the load (in this case, the load is represented with a lamp).

The DC voltage required by the light sensor circuit is supplied from a battery or by using a bridge rectifier circuit. This bridge rectifier circuit converts the 230v AC supply into a 6v DC. The bridge rectifier circuit utilizes a step-down transformer to step-down the 230v into 12v. The diodes connected in the form of a bridge are used to convert the 12v AC into 12v DC. The IC7806 DC voltage regulator is used to convert the 12v DC into 6v DC, and then, this 6V DC is supplied to the circuit. A 230v AC supply for both the load and the bridge rectifier is to be maintained continuously for uninterrupted operation of the light sensor circuit.

During the daytime, the light sensor LDR has very-low resistance of around a few 100Ω. Thus, the supply passes through the LDR and ground through the resistor and variable resistor as shown in the light sensor circuit. This is due to the fact that the resistance offered by the LDR during daytime or when the light is illuminated on LDR is less compared to the resistance of the remaining part of the circuit (that is through relay and Darlington pair). We are aware of the principle of current, that the current always flow in the low resistance path.

Thus, the relay coil does not get enough supply to get energized. Hence, the load is switched off during the daylight.

Similarly, during the night time (when the light illuminated on LDR is very less), the LDR resistance increases to a very high value of around a few Mega ohms (approximately 20MΩ). Thus, due to very high resistance of LDR the current flow is very less or almost zero like an open circuit condition. Now, the current flows through the low-resistance path such that it increases base voltage of Darlington pair to reach more than 1.4v. As the Darlington pair is activated, the relay coil gets enough supply to get energized, and hence, the load is switched on during night time or when no light is illuminated on LDR.

Practical Applications of Light Sensor Circuit

The light sensor circuit can be used to design various practical embedded systems based sensor based projects such as security alarm system by photo electric sensor, Arduino managed high sensitive LDR based power saver for street light control system, a solar highway lighting system with auto turn off in daytime, sunset to sunrise lighting switch, and so on.

Sunset to Sunrise Lighting Switch

The sunset to sunrise lighting switch is an application of light sensor circuit that is designed to control the automatically based on the light illuminated on the LDR light sensor.

The LDR resistance changes with the change in light intensity illuminated on LDR. The LDR output is given to 555 timer connected in bistable mode. The 555 timer output is used to control the triggering of load through a TRIAC. Thus, this light sensor circuit switches on the load in the evening or sunset and switches off the load in the morning or sun rise automatically.

Please refer to this link to know more about Embedded Systems Role in Automobiles.

Please refer to this link to know more about Ultrasonic Sensor MCQs & Humidity Sensor MCQs.

Hope, this article provides adequate information about how to make a light sensor circuit and its working operation. For designing innovative electrical and electronics projects on your own you can approach us by posting your ideas and comments in the comments section below.

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Light Sensor - Circuit Diagram, Working and Its Applications

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This Article Discusses an Overview of What is a Light Sensor, Circuit Diagram, Working Principle, Characteristics and Its Applications

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Gas sensors can be used to detect gas explosions , and it can also measure the gas's concentration. Gas sensors can be used in projects to detect gas spillage.

Source: https://www.fierceelectronics.com/sensors/what-a-gas-sensor#:~:text=They%20are%20commonly%20used%20to,%2C%20range%2C%20and%20sensing%20ability.

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A sensor that detects smoke from tiny particles in the air. Once they detect those particles then they would have a really loud alarm that will go to the authorities.

Project 1- Low-cost fire detector for house owners You can use it to sell to house owners in case of a fire.

Project 2-Fire alarm sensor for classrooms- In case of a fire in a classroom there would be a smoke detector that will let out a noise for the authorities to help.

https://www.nist.gov/how-do-you-measure-it/how-do-smoke-detectors-work#:~:text=Smoke%20alarms%20detect%20fires%20by,to%20safety%20and%20call%20911.

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Smoke alarms save lives. According to the National Fire Protection Association (NFPA), having working smoke alarms in your home cuts your risk of dying in a fire by 55%.

But how do smoke alarms work in the first place?

Smoke alarms detect particles in the air. They most commonly do this using two types of detection technologies.

First, there are ionization detectors. These use a small bit of safely shielded radioactive material that electrically charges, or ionizes, the air molecules between two metal plates. This produces a small electric current flowing from one plate to the other in the air. When particles enter the chamber, they attract the ions and carry them away, reducing the current. When the number of particles entering the chamber is enough to reduce that current below a certain amount, the device will register those particles as smoke and the alarm will sound. (And about that radioactive material? Most of its radiation is blocked inside the device, and even then, the radiation levels in the device are much lower than the natural background radiation to which we are exposed every day.)

The other type of commonly used detection technology is called photoelectric. This technology works by detecting light that is reflected off particles from a light beam inside the sensing chamber. When no particles are present in the sensing chamber, the light from the beam does not strike the light detector, indicating all clear. When there are particles present and the amount of light registered by the light detector reaches a certain threshold level, the alarm sounds.

Both kinds of detectors can detect either slow-burning "smoldering" fires or fast-burning "flaming" fires, but each technology has its particular strengths. Ionization-based alarms tend to detect small black soot particles from flaming fires more quickly because they are produced in greater numbers and take away more current from between the plates. Photoelectric detectors tend to be more sensitive to particles that are larger in size and white or light-colored, and thus more reflective, like those emitted by smoldering fires.

The NFPA advises that people have both ionization and photoelectric units in their homes. And dual-sensor alarms that combine both technologies are also available.

As important as smoke alarms are for protecting your family and your property, many times they can be a nuisance. Smoke alarms near kitchens can detect the particles coming off your food as it cooks, even if you don't burn it. Sometimes something as simple as turning on a toaster can set them off.

So as with many safety measures, smoke detectors have a trade-off. They can be made sensitive enough to detect almost any smoke. But if they did, they would detect the smoke you don't want them to detect (such as from cooked food) and even other things such as dust. Less sensitive detectors would have fewer nuisance alarms, but in an actual fire, they may not go off in time to save lives or property. Or they may not give off a signal at all.

Researchers are developing new tests and standards to make smoke alarms better at detecting the kinds of smoke we want them to detect and not the kinds we don't, so we're never tempted to disable the alarms and put ourselves in danger. As a result, the next generation of smoke detectors promises to cut down on the number of nuisance alarms while also signaling real fires more quickly. And with fire, time is everything when it comes to saving lives and property.

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Smoke alarms work by detecting particles in the air.

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A touch sensor's function is to capture touch from an object/ person and record it to perform a designated task.

project examples-
A chest with a touch sensor that unlocks when the sensor is activated is put on it.

A dispenser that pours a liquid of your choice  when the touch sensor is activated. The amount of liquid poured can be adjustable.

source- https://in.element14.com/sensor-touch-sensor-cap-res-technology#:~:text=A%20touch%20sensor%20is%20a,a%20human%20user%20or%20operator.

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also known as a color recognition sensor, is a device that senses color of an object based on the light reflected from it , it can be used in color detection and identification color sensors can recognize and detect colors when processing images.

https://www.watelectronics.com/what-is-color-sensor-working-its-applications/

https://www.keyence.com/ss/products/sensor/sensorbasics/color/info/

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Function

2 projects

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Function:
An Ultra Sonic Sensor works by emmiting sound waves, which humans cannot hear. The waves hit a target and bounce back as an echo. Measuring the time it took for the sound waves to reach and come back, the sensor then uses this information to determine the distance between the sensor and the target.

Uses:
Supersonic sensors can be used to detect an object and they can also be used to map a certain area.

Source:
Carlson, Cody. “How Ultrasonic Sensors Work.” MaxBotix, MaxBotix, Mar. 2023, maxbotix.com/blogs/blog/how-ultrasonic-sensors-work. Accessed 26 July 2023.

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Pick 3 sensors: Function of the sensor, 2 ways in which the sensor can be used in a project. Provide links from where you are getting the information.