PIR Motion Sensor

Alarms area unit quite common today, a lot of individuals have alarms within the whole house. however what if you wish your internal alarm? for instance, you’ll wish to prevent your siblings from coming into your space, this project can assist you to build a straightforward PIR motion detector mistreatment the Arduino Uno board.

This project won’t have any form of switch flip|to show} it off that the sole thanks to stopping it’s to urge out of the area wherever it’s put in or turn down the facility. This project will offer a glimpse of however the tone operates works.

How PIR Motion Sensor Works

First, let’s make a case for the working rule. The module truly consists of a pyroelectrical device that generates energy once exposed to heat.

That means once a person’s or animal body can get within the vary of the device it’ll discover a movement as a result of the human or animal body emits heat during a type of infrared. That’s wherever the name of the device comes from, a Passive Infra-Red device. and also the term “passive” implies that the device isn’t exploitation any energy for detection functions, it simply works by detection the energy given off by the opposite objects.

The module additionally consists a specially designed cowl named lens, that focuses the infrared signals onto the pyroelectrical device.

The HC-SR501 PIR Sensor Module

The module has simply 3 pins, a Ground ANd a VCC for powering the module ANd an output pin which supplies high logic level if an object is detected. conjointly it’s 2 potentiometers. One for adjusting the sensitivity of the detector and also the different for adjusting the time the signaling stays high once the object is detected. now is adjusted from zero.3 seconds up to five minutes.


The module has 3 additional pins with a jumper between 2 of them. These pins ar for choosing the trigger modes. the primary one is termed “non-repeatable trigger” and works like this: once the detector output is high and also the delay time is over, the output can mechanically modification from high to low level. the opposite mode known as “repeatable trigger” can keep the output high all the time till the detected object is gift in sensor’s vary.

Components Parts needed

You can get the components from any of the sites below:

*Please note: These are affiliate links. I may make a commission if you buy the components through these links. I would appreciate your support in this way!

PIR sensor project with Arduino

First thing we’ve to try  to, before uploading the program is obtaining the connections prepared. you’ll would like five Jumper wires to attach everything, all of those wires ought to have male-female connectors.

Now it’s time to transfer the program to Arduino. within the comments, you’ll be able to notice rationalization of the full code. I set the frequency to 3000 Hertz as a result of I found on the web that the majority alarms use this frequency. The PIR sensing element is essentially movement sensing element therefore whenever it detects movements, it sets bent on HIGH, you’ll be able to manage the time of this HIGH state and therefore the sensitivity of your sensing element with the two potentiometers shown on the image below.

Source Code

Watch to Youtube Video