Turns on a series of LEDs based on the value of an analog sensor.

  This is a simple way to make a bar graph display. Though this graph

  uses 10 LEDs, you can use any number by changing the LED count

  and the pins in the array.

  This method can be used to control any series of digital outputs that

  depends on an analog input.

  The circuit:

   * LEDs from pins 2 through 11 to ground

 created 4 Sep 2010

 by Tom Igoe 

 This example code is in the public domain.

 http://www.arduino.cc/en/Tutorial/BarGraph

 */

// these constants won't change:

const int analogPin = A0;   // the pin that the potentiometer is attached to

const int ledCount = 10;    // the number of LEDs in the bar graph

int ledPins[] = { 

  2, 3, 4, 5, 6, 7,8,9,10,11 };   // an array of pin numbers to which LEDs are attached

void setup() {

  // loop over the pin array and set them all to output:

  for (int thisLed = 0; thisLed < ledCount; thisLed++) {

    pinMode(ledPins[thisLed], OUTPUT); 

  }

}

void loop() {

  // read the potentiometer:

  int sensorReading = analogRead(analogPin);

  // map the result to a range from 0 to the number of LEDs:
  int ledLevel = map(sensorReading, 0, 1023, 0, ledCount);

  // loop over the LED array:

  for (int thisLed = 0; thisLed < ledCount; thisLed++) {

    // if the array element's index is less than ledLevel,

    // turn the pin for this element on:

    if (thisLed < ledLevel) {

      digitalWrite(ledPins[thisLed], HIGH);

    } 

    // turn off all pins higher than the ledLevel:

    else {

      digitalWrite(ledPins[thisLed], LOW); 

    }

  }

}

int led_red = 0; // the red LED is connected to Pin 0 of the Arduino

int led_yellow = 1; // the yellow LED is connected to Pin 1 of the Arduino

int led_green = 2; // the green LED is connected to Pin 2 of the Arduino

int led_blue = 3; // the green LED is connected to Pin 3 of the Arduino

void setup() {

  // set up all the LEDs as OUTPUT

  pinMode(led_red, OUTPUT);

  pinMode(led_yellow, OUTPUT);

  pinMode(led_green, OUTPUT);

  pinMode(led_blue, OUTPUT);

}

void loop() {

  // turn the green LED on and the other LEDs off

  digitalWrite(led_red, LOW); 

  digitalWrite(led_yellow, LOW);

  digitalWrite(led_green, HIGH);

  digitalWrite(led_blue, LOW);

  delay(1000);    // wait 2 seconds

  // turn the yellow LED on and the other LEDs off

  digitalWrite(led_red, LOW);   

  digitalWrite(led_yellow, HIGH);

  digitalWrite(led_green, LOW);

  digitalWrite(led_blue,LOW);

  delay(2000);   // wait 1 second

  // turn the red LED on and the other LEDs off

  digitalWrite(led_red, HIGH);  

  digitalWrite(led_yellow, LOW);

  digitalWrite(led_green, LOW);

  digitalWrite(led_blue, LOW);

  delay(3000);  // wait 3 seconds  

  // turn the blue LED on and the other LEDs off

  digitalWrite(led_red, LOW);  

  digitalWrite(led_yellow, LOW);

  digitalWrite(led_green, LOW);

  digitalWrite(led_blue, HIGH);

  delay(4000);  // wait 3 seconds    

}
3.  MEASURE DISTANCE

// Pinul Trigger de la senzor la pinul 9 de pe Arduino

#define TRIGGER 9 

// Pinul Echo de la senzor la pinul 8 de pe Arduino

#define ECHO 8

// aceasta variabila salveaza cat timp are nevoie un sunet pentru a reflecta si a reveni inapoi

//valoarea initiala este zero

long durata=0;

//variabila care salveaza distanta masurata

long distanta=0; 

void setup() {

pinMode(TRIGGER, OUTPUT); // trigger pin este iesire

pinMode(ECHO, INPUT); // echo pin este intrare

Serial.begin(9600); //pornesc comunicarea seriala astfel incat pot vedea valorile masurate

}

void loop() {

 digitalWrite(TRIGGER, LOW); // aici oprim tensiunea pentru o perioada scurta de timp la trigger

 delayMicroseconds(2); // durata de 2 microsecunde

 digitalWrite(TRIGGER, HIGH); // acum trimitem un sunet

 delayMicroseconds(10); // durata de 10 microsecunde

 digitalWrite(TRIGGER, LOW); // oprim sunetul

 durata = pulseIn(ECHO, HIGH); // Cu comanda "pulseIn" arduino contorizeaza timpul in microsecunde pana cand sunetul revine la senzorul cu ultrasunete

distanta = (durata/2) * 0.03432;

//daca distanta masurata este de peste 500 centimetrii sau sub 0 cm...

if(distanta >= 500 ||  distanta <=0) {

 // monitorul serial va afisa acest text deoarce valorile masurate in aceste zone sunt gresite sau inexacte

  Serial.println ("nu am chef sa masor asta");

} else //in caz contrar 

{

Serial.print(distanta); // valoarea distantei va fi afisata pe monitor

Serial.println(" cm");

}

delay(1000);

}