PIR Sensor

I am building a PIR sensor Arduino Alarm. And my PIR sensor is continuously sensing and not stopping.(i.e by buzzer o/p). I just want to know how to stop it from continuously buzzing and how to set the best sensitivity of PIR Sensor. And how to manually test the PIR sensor via multimeter?

code:

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);
}
}

Use code tags </> around your code-makes it easier to read.

PIR sensor is a digital output- you can measure the voltage using your multimeter: around 5V for HIGH, around 0v for LOW.

Your code appears to be OK, I wonder if you have a wiring error thats keeping the input on all the time.

rw950431: you can measure the voltage using your multimeter: around 5V for HIGH, around 0v for LOW.

Small PIR sensors have an onboard 3.3volt regulator, so 3.3volt for "high". 5volt Arduinos have no problem with this "high", because the "high" switchpoint is 0.6*VCC (3volt).

Leave "sensitivity" pot in the middle. Turn "time" pot fully anti-clockwise (leave timing over to the Arduino, not to the sensor). Leo..

rw950431: Your code appears to be OK

It should be.... I recognise it as adafruit's PIR tutorial