/* * Ultrasonic Sensor HC-SR05/4 and Arduino * by Hanie Kiani * https://electropeak.com/learn */ long duration; int distance; const int trig = 9; const int echo = 10; void setup() { pinMode(trig, OUTPUT); // Sets the trigPin as an Output pinMode(echo, INPUT); // Sets the echoPin as an Input Serial.begin(9600); // Starts the serial communication } void loop() { distance = calculateDistance(); Serial.println(distance); } int calculateDistance(){ digitalWrite(trig, LOW); delayMicroseconds(2); // Sets the trigPin on HIGH state for 10 micro seconds digitalWrite(trig, HIGH); delayMicroseconds(10); digitalWrite(trig, LOW); duration = pulseIn(echo, HIGH); // Reads the echoPin, returns the sound wave travel time in microseconds distance= duration*0.034/2; return distance; }