Robotics Training LESSON 16: Using the HC-SR04 Ultrasonic Sensor for Echolocation

In this lesson we explain the concept of echolocation, and how the HC-SR04 ultrasonic sensor can be used to measure the time it takes a ping to go out, bounce off a target and come back. From this ping travel time, it is possible to precisely calculate the distance to the target. For your convenience, the code we developed is included below.

int Trig=A5;
int Echo=A4;
int pingT;
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:
pingT=pingTime();
Serial.println(pingT);
delay(500);

}

int pingTime(){
  int pingTravelTime;
  digitalWrite(Trig, LOW);   
  delayMicroseconds(2);
  digitalWrite(Trig, HIGH);  
  delayMicroseconds(20);
  digitalWrite(Trig, LOW);   
  pingTravelTime = pulseIn(Echo, HIGH);        
  return pingTravelTime; 
}

int Trig=A5;

int Echo=A4;

int pingT;

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:

pingT=pingTime();

Serial.println(pingT);

delay(500);

}

int pingTime(){

int pingTravelTime;

digitalWrite(Trig, LOW);

delayMicroseconds(2);

digitalWrite(Trig, HIGH);

delayMicroseconds(20);

digitalWrite(Trig, LOW);

pingTravelTime = pulseIn(Echo, HIGH);

return pingTravelTime;

}

Making The World a Better Place One High Tech Project at a Time. Enjoy!