Example Code for Arduino-Distance Measurement

Wiring Diagram

Sample Code

#include "Arduino.h"

/*
 Trig:  Measurement trigger pin - Low level pulse over 50us triggers one distance measurement.
 Holding this pin LOW will repeats the measurement every 100ms.
 */
#define  TRIGGER   2

/*
 ECHO: Pulse signal output pin – 1us high level pulse equals 1mm in distance.
 If error occurs in detection, a 15000us high level pulse will be generated.
 */
#define  ECHO      3

void setup()
{
  pinMode(TRIGGER, OUTPUT);
  digitalWrite(TRIGGER, HIGH);
  pinMode(ECHO, INPUT);
  Serial.begin(9600);
}
void loop()
{
  // generate the pulse to trigger the sensor
  digitalWrite(TRIGGER, LOW);
  delayMicroseconds(50);
  digitalWrite(TRIGGER, HIGH);
  delayMicroseconds(50);

  //read the time of the pulse. 1us equals 1mm.
  int distance = pulseIn(ECHO,HIGH);

  Serial.print("distance:");
  Serial.print(distance);
  Serial.println("mm");
  delay(500);
}

Additional Information