By Renpeng Zhang

HC-SR04 range test

Table

Range HC-SR04 was tested

Code

/*

* 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);

 delayMicroseconds(2);

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

 digitalWrite(trigPin, HIGH);

 delayMicroseconds(10);

 digitalWrite(trigPin, LOW);

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

 duration=pulseIn(echoPin, HIGH);

 // Calculating the distance

 distance=duration*.034/2-1;

 // 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.print(distance);

 Serial.println(” cm”);

 delay(500);

}

Output

Source

http://howtomechatronics.com/tutorials/arduino/ultrasonic-sensor-hc-sr04/