HC-SR04 Ultrasonic Distance Sensor Audio Alert with Arduino

With an HC-SR04 and a Piezo Buzzer you can create an audio distance sensor like the one many cars have for backing up.

Functional Parts in the Project:

• Arduino Uno – https://store.arduino.cc/usa/arduino-uno-rev3
• HC-SR204 Ultrasonic Sensor – https://amzn.to/31AGgYC
• Breadboard Kit – https://amzn.to/2Xih5ei
• Piezo Buzzer – https://amzn.to/2F961py

#define trigPin 8
#define echoPin 9
#define buzzer 10

long duration;
float distanceInch;
int timer;

void setup() {
pinMode(trigPin, OUTPUT); 
pinMode(echoPin, INPUT); 
pinMode(buzzer, OUTPUT);
}

void loop() {
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);

duration = pulseIn(echoPin, HIGH);

distanceInch = duration * 0.0133 /2;

digitalWrite(buzzer, HIGH);
delay(50);
digitalWrite(buzzer, LOW);

timer = distanceInch * 10;

delay(timer);
}