HC-SR04 is an ultrasonic sensor that measures distances from 2 to 400cm.
This is a simple library for it!
Sensor is initialized by creating instance of class UltraSonicDistanceSensor and providing trigger and echo pins:
UltraSonicDistanceSensor sensor(triggerPin, echoPin);
.
Then, to measure the distance, you just call measureDistanceCm()
, which will return distance in centimeters (double). If distance is larger than 400cm, it will return negative value.
In this simple example, we need to connect sensors pins like this:
- vcc to 5V
- trig to digital pin 13
- echo to digital pin 12
- gnd to gnd
#include <HCSR04.h>
// Initialize sensor that uses digital pins 13 and 12.
int triggerPin = 13;
int echoPin = 12;
UltraSonicDistanceSensor distanceSensor(triggerPin, echoPin);
void setup () {
Serial.begin(9600); // We initialize serial connection so that we could print values from sensor.
}
void loop () {
// Every 500 miliseconds, do a measurement using the sensor and print the distance in centimeters.
double distance = distanceSensor.measureDistanceCm()
Serial.println(distance);
delay(500);
}