PIR Sensor Detecting Object Using Arduino

Introduction

Figure1: PIR Sensor

It is used to detect the human being moving around approximately 10m from sensor.
The actual range is between 5m to 12m.
It is of high sensitivity and low noise.

Parts Of List

Connection To An Arduino Board

LED

Buzzer

Figure 2: Buzzer

Connection

Programming

int ledPin = 7; // choose the pin for the LED
int inputPin = 5; // 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);
}
}

Explanation

In this concept the PIR sensor can act as the night security alarm at a particular distance. For example, we kept things on the table. If anybody touches them then there is an alert that produce sound.

Programming Explanation

Play tone means the value of the buzzer when it produced the sound.
If the Led is on the buzzer produced the sound and they mention the value.
If the Led is off the buzzer can't produce the sound then they could not mention the value.

Application