int TRIG=10;
int ECHO=7;
float duration,distance;
void setup() {
  // put your setup code here, to run once:
pinMode(TRIG, OUTPUT);
pinMode(ECHO, INPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(TRIG, HIGH);
delayMicroseconds(20);
digitalWrite(TRIG, LOW);
delayMicroseconds(20);
duration=pulseIn(ECHO,HIGH);
distance=0.017*duration;
Serial.print("distance");
Serial.print(distance);
Serial.println("cm");
delay(1000);
}