HC-SR04 Ultrasonic Sensor Test

By Renpeng Zhang

HC-SR04 range test


Range HC-SR04 was tested



* HC-SR04 testing code

* Connect Vcc to 5V

* Connect Gnd to Gnd

* Connect Trig to pin 9(PWM)

* Connect Echo to pin 10(PWM)



// defines pins numbers

const int trigPin=9;

const int echoPin=10;


// defines variables

long duration;

double distance;


void setup() {

 pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output

 pinMode(echoPin, INPUT); // Sets the echoPin as an Input

 Serial.begin(9600); // Starts the serial communication


void loop() {

 // Clears the trigPin

 digitalWrite(trigPin, LOW);


 // Sets the trigPin on HIGH state for 10 micro seconds

 digitalWrite(trigPin, HIGH);


 digitalWrite(trigPin, LOW);

 // Reads the echoPin, returns the sound wave travel time in microseconds

 duration=pulseIn(echoPin, HIGH);

 // Calculating the distance


 // the -1 is to factor in the error of my specific sensor and put it into consideration

 // Prints the distance on the Serial Monitor

 Serial.print(“Distance: “);


 Serial.println(” cm”);







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