PIR Sensor Based Motion Detector/Sensor Circuit


ByJayant 39

PIR Motion Detector/Sensor Circuit Diagram

Passive Infrared Sensor (PIR) is very useful module, used to build many kinds of Security Alarm Systems and Motion Detectors. It is called passive because it receives infrared, not emits. Basically PIR sensor detects any change in heat, and whenever it detects any change, its output PIN becomes HIGH. They are also referred as Pyroelectric or IR motion sensors.

Here we should note that every object emits some amount of infrared when heated. Human also emits infrared because of body heat. PIR sensors can detect small amount of variation in infrared. Whenever an object passes through the sensor range, it produces infrared because of the friction between air and object, and get caught by PIR.

The main component of PIR sensor is Pyroelectric sensor shown in figure (rectangular crystal behind the plastic cap). Along with this, BISS0001 ("Micro Power PIR Motion Detector IC"), some resistors, capacitors and other components used to build PIR sensor. BISS0001 IC take the input from sensor and does processing to make the output pin HIGH or LOW accordingly.

PIR Sensor

Pyroelectric sensor divide in two halves, when there is no motion, both halves remain in same state, means both senses the same level of infrared. As soon as somebody enters in first half, the infrared level of one half becomes greater than other, and this causes PIRs to react and makes the output pin high.

Pyroelectric sensor is covered by a plastic cap, which has array of many Fresnel Lens inside. These lenses are curved in such a manner so that sensor can cover a wide range.

We have built a very simple Motion detector circuit here. We are using a HC-SR501 PIR Sensor, an LED (which will glow whenever there is a motion infront of the sensor) and resistor. Vcc PIN of PIRs connected to the positive terminal of the 9v battery, GND pin is connected to negative terminal of battery and Output pin of PIR is connected to LED with a resistor of 220 Ohm. When there is any motion in the range of PIRs, LED will start blinking.


Circuit Components

  • PIR Sensor (we used HC-SR501)
  • Resistor 220ohm (any resistor below 1k ohm)
  • LED
  • Battery (5-9V)


Circuit Diagram and Explanation

PIR Motion Detector/Sensor Circuit Diagram

PIRs takes some time to stable itself according to surrounding conditions, so you can find, LED turn ON and OFF randomly for about 10-60 seconds.

Now when we find the LED blinking whenever there is any motion, look back of the PIR, you will find a jumper which is placed between outer corner PIN and middle PIN (see diagram above). This is called “non-retriggering” Or “Non-repeatable trigger” and jumper said to be in L position. In this position LED will blink continuously until there is motion.

Now if you connect this jumper between inner corner PIN and middle PIN, then LED will stay on all the time till there is any motion. This one is called “retriggering” or “Repeatable trigger” and jumper said to be in H position.

PIR Sensor Components

There are two potentiometers (shown in above figure), used to set the time delay and distance range. Time delay is the duration in which the LED will remain ON (out pin HIGH). In Non repeatable triggering, OUTPUT will become low automatically after the time delay. In Repeatable triggering OUTPUT will also become low after time delay, but if there is a continuous human activity; OUTPUT will remain HIGH even after the time delay.

Turn the Distance Adjustment potentiometer clockwise rotation, increased sensing distance (about 7 meters), on the other hand, the sensing distance decreases (about 3 meters).

Turn the Time delay potentiometer clockwise rotation sensor the delay lengthened (600S, 10 minutes), on the opposite side, shorten the delay (0.3 second).

Generally PIR detects infrared of 8 to 14 micrometre of wavelength and has range of 3-15 meters with a field of view less than 180 degrees. This range can vary upon different models. Some ceiling PIRs can cover 360 degrees. PIRs generally operate at 3-9V DC.


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  • Shivam Sahil's picture
    Shivam Sahil
    Sep 17, 2017

    Most of them could detect upto 20 feet whereas some of them may go till 30 feet

  • basith's picture
    Jan 07, 2016

    sir ...this circuit also good

    but this is only active when human actions there's no actions or movement no response
    sir..I riqstng u
    I want a circuit tht active when human enterd and deactivate if human absantsts

    plz rply me soon as possible

  • Jayant's picture
    Jan 14, 2016

    I am not getting you, this circuit is already working as per your need. The LED/alarm gets only activated in human presence.

  • ram's picture
    Oct 16, 2016

    he is right, bcoz its activate on human motion capture, if there is a no movement and also person is present but not moving.then its get off after sated time

  • Ediyo 's picture
    Jan 25, 2017

    I wish to understand, can this circuit not be used in a room? What I mean is, in a room, you may have other things that generate heat light fan, refrigerator, TV set and you can also have an Air conditioner.

    In such a situation, can the system work very well? Or should it be limited to work only on passage ways and stair case?

  • Enrico's picture
    Feb 18, 2016

    sir..can you make it turn off when the person exits the room?
    for example:
    when the person enters the room, the sensor detect the person and turns on the light, and when the person gets out from the room, the sensor detect the person and turns off the light.
    im trying to make this for my bathroom light, can you help me?

  • Awes's picture
    Feb 29, 2016

    how to make,when pir detect motion then all alarm should ring continouse till we switch off and on pir circuit.

    it is because the pir ring buzzer for very short period.

  • Maddy's picture
    Mar 11, 2016

    Read the working of PIR sensor carefully, you can increase the Period by using the Time delay control knob.

  • GOPINATH G's picture
    Feb 29, 2016

    sir, In my PIR sensor the output pin always goes high even if there is no motion detected, I even tuned the sensitivity and delay,but i cant, plz help me !.........

  • Sammy's picture
    Jun 06, 2016


    I want that when my sensor detects it turns on the alarm and alarm should remain on till alarm 3-4 minutes.

  • Maddy's picture
    Jun 11, 2016

    You can set the time delay using Time delay potentiometer, upto 10 minutes. Please read the article carefully.

  • VEERAMANI Ayyandurai's picture
    VEERAMANI Ayyandurai
    Jun 15, 2016

    we are facing color wire interchanging problem in our process, we need correct color presence or not identification by using simple circuit,it is possible pls send me quote to my email id along with project details at soon.

  • Mohan Kamadi's picture
    Mohan Kamadi
    Sep 02, 2016

    SIr plz tell me the price of PIR sensor, And Where I purchase it.

  • Guru 's picture
    Sep 18, 2016

    simly go to amazon site then searh select and by

  • Manzoor khan's picture
    Manzoor khan
    Sep 07, 2016

    wtat is the range of pir sensor one pir sensor number of lights to connet

  • sudeep mishra's picture
    sudeep mishra
    Oct 05, 2016

    what will hppn if some small creature or animal in front of a sensor ???

  • Didier's picture
    Nov 22, 2016

    working range is 5m

  • Sayeed Ahmed's picture
    Sayeed Ahmed
    Dec 26, 2016

    Can I use 12V Battery???

  • hmza's picture
    Apr 25, 2017

    sir ...this circuit also good
    but this is only active when human actions there's no actions or movement no response
    sir..I requesting u
    I want a circuit that active when human entered and deactivate if human absense
    plz rply me soon as possible

  • ashwini's picture
    Jun 02, 2017

    motion sensor turns the light on if there is human action...but does not when human present in the room but without any movement...how to solve this issue ..how to write code for this ..??
    please reply as soon as possible..

  • vince jack ludovice's picture
    vince jack ludovice
    Aug 04, 2017

    can i use pcb for this circuit

  • Nath.'s picture
    Sep 06, 2017

    I have a question, does it work with a light and alarm or can it be connected to both?
    When someone enters, the light on and the alarm goes on as well,..
    And can it be connected on the fence of a house?

  • Aswinth Raj's picture
    Aswinth Raj
    Sep 06, 2017

    You can use the output pin of the sensor to drive any load you want. The load might be Light Alaram ar anything that you desire. But you should design apprpriate driver circuit for it.


  • Biswa's picture
    Jul 30, 2018

    Hi Aswinth , Hope you are doing good .

    Need your help on below , i had a small water fountain which run with (1) MINI WATER PUMP DC 3V-9V and (2) 9v Bettery , i would like to add per motion to it , i tried but the motor is running , could you please help me how can i do that ,(i have zero knowledge with apprpriate driver circuit for)

    Advance thank you for your help

  • Yajash Goplani's picture
    Yajash Goplani
    Mar 15, 2018

    Can we increse its range??

  • amardeeptulla's picture
    Mar 27, 2018

    if i have to use more than 1 PIR sensor in my circuit can i draw 5 v power for each using only 1 5v power pin on arduino .

  • Shikhar khare's picture
    Shikhar khare
    Mar 27, 2018

    I need Complete Block circuit of This PIR sensor . can you please share that with me .

  • jawad ul-haque's picture
    jawad ul-haque
    Mar 28, 2018

    Is there one specific resistor which can be used for the PIR sensor or is a there a number of resistors which can be used for the PIR motion sensor ?, if so what are the names of the resistors ?

  • Rithik Goyal's picture
    Rithik Goyal
    May 31, 2018

    can someone provide me with a circuit for making a PIR sensor for human detection?

  • LEVI's picture
    Jun 14, 2018

    Please how can I incorporate a delay system to this PIR so that it doesn't come on immediately it senses the motion. I want a system that will have a delay of 30seconds before the PIR triggers the LED to be HIGH?

  • AISHA's picture
    Jun 18, 2018

    You have to create a Delay circuit using 555 Timer 

  • varma's picture
    Jul 21, 2018

    I want check message get my phone when detect the pir motion sensor , Then it is possible for this feature, please send me reply quickly

  • Jay's picture
    Jul 20, 2019

    As with your other articles, this one is also very informative. I have always been foxed about both the presets, but this cleared them up for me. Also, I didn't know there was a non-retriggerable option.

    Thanks for sharing. Please do keep contributing.

  • Jay's picture
    Jul 20, 2019

    Jayant, is there a way to increase the sensitivity on these PIR modules?

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