/*
ULTRASONIC SENSOR 18.02.2020
 */
const int trigPin = A0;
const int echoPin = A1;
int out6 = 4 ;
// defines variables
long duration, cm, inches;
void setup() {
  Serial.begin(9600); 
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input
  pinMode(out6, OUTPUT);   
  }
void loop() {
  // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(5);
  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Reads the echoPin, returns the sound wave travel time in microseconds
  pinMode(echoPin, INPUT);    
  duration = pulseIn(echoPin, HIGH);
  // Calculating the distance
  cm = (duration/2)/29.1;
  Serial.println(cm);
  if (cm < 30) // obsticle detected
  { 
    analogWrite(out6, cm); 
//    delay(200);    
  }
  else
  {
    analogWrite(out6, 0);
  }
}