Ping))) Ultrasonic Sensor

Introduction

Parallax's Ping))) sensor is an ultrasonic sensor that is used for distance measurements.

Ultrasonic sensors work by sending out a sound wave and waiting until that wave bounces back to the sensor. This means that the sensor's accuracy can actually change with the speed of sound. However, this is usually not an issue.

The advantage of the Ping sensor over similar ultrasonic sensors is that it only has three pins: +5V, GND, Trigger. This means that one less pin is used on the Arduino, which may be crucial to a project.

Coding the Ping

Coding the Ping is very simple since there is an Arduino example code included in the IDE under: File >> Examples >> 06.Sensors >> Ping.

This gives the basic code to get it Ping operating. To integrate this into code, it may not be necessary to read the sensor everytime, so putting a timer on it may be advantageous:

long previousMillis = millis();
int PingPin = 7;

void setup() {
  Serial.begin(9600);
}

void loop() {
  int interval = 1000;
  long duration;
 
  if(millis() - previousMillis > interval) {
    //Ping is triggered
    pinMode(pingPin, OUTPUT);
    digitalWrite(pingPin, LOW);
    delayMicroseconds(2);
    digitalWrite(pingPin, HIGH);
    delayMicroseconds(5);
    digitalWrite(pingPin, LOW);
    pinMode(pingPin, INPUT);
    duration = pulseIn(pingPin, HIGH);

    previousMillis = millis();
  }
}

This is a simple way to trigger the sensor only when the interval of time has passed.