//Ultrasonic Distance alarm by Madhusoodhan T.G const int trigPin = 9; const int echoPin = 10; const int buzzer = 11; const int ledPin = 13; // defines variables long duration; int distance; int safetyDistance; void setup() { pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output pinMode(echoPin, INPUT); // Sets the echoPin as an Input pinMode(buzzer, OUTPUT); pinMode(ledPin, OUTPUT); 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*0.034/2; safetyDistance = distance; if (safetyDistance <= 80){ //Enter the Distance digitalWrite(buzzer, HIGH); digitalWrite(ledPin, HIGH); } else{ digitalWrite(buzzer, LOW); digitalWrite(ledPin, LOW); } // Prints the distance on the Serial Monitor Serial.print("Distance: "); Serial.println(distance); }