// Uses a PIR sensor to detect movement, buzzes a buzzer
int ledPin = 13; // choose the pin for the LED int inputPin = 2; // choose the input pin (for PIR sensor) int pirState = LOW; // we start, assuming no motion detected int val = 0; // variable for reading the pin status int pinSpeaker = 10; //Set up a speaker on a PWM pin (digital 9, 10, or 11)
void setup() { pinMode(ledPin, OUTPUT); // declare LED as output pinMode(inputPin, INPUT); // declare sensor as input pinMode(pinSpeaker, OUTPUT); Serial.begin(9600); }
void loop(){ val = digitalRead(inputPin); // read input value if (val == HIGH) { // check if the input is HIGH digitalWrite(ledPin, HIGH); // turn LED ON playTone(300, 160); delay(150);
if (pirState == LOW) {
// we have just turned on
Serial.println("Motion detected!");
// We only want to print on the output change, not state
pirState = HIGH;
}
} else {
digitalWrite(ledPin, LOW); // turn LED OFF
playTone(0, 0);
delay(300);
if (pirState == HIGH){
// we have just turned off
Serial.println("Motion ended!");
// We only want to print on the output change, not state
pirState = LOW;
}
}
}
// duration in mSecs, frequency in hertz
void playTone(long duration, int freq) {
duration *= 1000;
int period = (1.0 / freq) * 1000000;
long elapsed_time = 0;
while (elapsed_time < duration) {
digitalWrite(pinSpeaker,HIGH);
delayMicroseconds(period / 2);
digitalWrite(pinSpeaker, LOW);
delayMicroseconds(period / 2);
elapsed_time += (period);
}
}