#define trigger 8
#define echo 7
long timeNeeded;
float distance;


void setup() {
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
    ; // wait for serial port to connect. Needed for native USB port only
    pinMode(trigger,OUTPUT); 
    pinMode(echo,INPUT); 
}

void loop() { // run over and over
      digitalWrite(trigger,LOW); 
      delayMicroseconds(2);
      digitalWrite(trigger, HIGH);
      delayMicroseconds(10);
      digitalWrite(trigger, LOW);
      timeNeeded = pulseIn(echo, HIGH);
      distance= timeNeeded * 0.034/2;
      Serial.println(distance);
      delay(1000);               
}