/*
 * created by Rui Santos, https://randomnerdtutorials.com
 * 
 * Complete Guide for Ultrasonic Sensor HC-SR04
 *
    Ultrasonic sensor Pins:
        VCC: +5VDC
        Trig : Trigger (INPUT) - Pin11
        Echo: Echo (OUTPUT) - Pin 12
        GND: GND
 */
 
int trigPin = 9;    // Trigger
int echoPin = 8;    // Echo
long duration, cm, inches;
int ledVerte = 10;
int ledJaune = 11;
int ledRouge = 12;
int buzzerAlerte = 7;

int duree = 250;
int note = 1000;

void setup() {
  //Serial Port begin
  Serial.begin (9600);
  //Define inputs and outputs
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  pinMode(ledVerte, OUTPUT);
  pinMode(ledJaune, OUTPUT);
  pinMode(ledRouge, OUTPUT);
  digitalWrite(ledVerte, LOW);
  digitalWrite(ledJaune, LOW);
  digitalWrite(ledRouge, LOW);

  pinMode(buzzerAlerte, OUTPUT);
  digitalWrite(buzzerAlerte, LOW);
}
 
void loop() {
  // The sensor is triggered by a HIGH pulse of 10 or more microseconds.
  // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
  digitalWrite(trigPin, LOW);
  delayMicroseconds(5);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
 
  // Read the signal from the sensor: a HIGH pulse whose
  // duration is the time (in microseconds) from the sending
  // of the ping to the reception of its echo off of an object.
  pinMode(echoPin, INPUT);
  duration = pulseIn(echoPin, HIGH);
 
  // Convert the time into a distance
  cm = (duration/2) / 29.1;     // Divide by 29.1 or multiply by 0.0343
  inches = (duration/2) / 74;   // Divide by 74 or multiply by 0.0135
  
  Serial.print(inches);
  Serial.print("in, ");
  Serial.print(cm);
  Serial.print("cm");
  Serial.println();

  if (cm > 200) 
  {
    digitalWrite(ledVerte, HIGH);
    digitalWrite(ledJaune, LOW);
    digitalWrite(ledRouge, LOW);
    duree = 500;
  }
  else if (cm > 60 && cm < 200)
  {
    digitalWrite(ledVerte, LOW);
    digitalWrite(ledJaune, HIGH);
    digitalWrite(ledRouge, LOW);
    duree = 250;
  }
  else
  {
    digitalWrite(ledVerte, LOW);
    digitalWrite(ledJaune, LOW);
    digitalWrite(ledRouge, HIGH);
    duree = 100;
     // turn off tone function for pin 7:
    //noTone(buzzerAlerte);
    // play a note on pin 6 for 200 ms:
    //tone(6, 440, 100);
    //tone(6, 440, duree);
  }
  
//  delay(250);
//  delay(duree);

// turn off tone function for pin 7:
  noTone(buzzerAlerte);
  // play a note on pin 6 for 200 ms:
  //tone(6, 440, 100);
  //tone(buzzerAlerte, note, duree);
}