const int trigPin = 13;
const int echoPin = 12;
const int BuzerPin= 9;
const int led1= 10;
long duration;
float distance;
void setup() {
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(led1, OUTPUT);
Serial.begin(9600);
}
void loop() {
// Trigger the sensor
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Read echo
duration = pulseIn(echoPin, HIGH);
distance = duration * 0.034 / 2;
// Control buzzer + LED
if (distance >0 && distance < 10) {
tone(BuzerPin, 1000); // 1kHz sound
digitalWrite(led1, HIGH);
}
else {
noTone(BuzerPin); // stop sound
digitalWrite(led1, LOW);
}
// Print distance
Serial.print("Distance: ");
Serial.print(distance);
Serial.println(" cm");
delay(500);
}