MagicMirror² v2.4.1 is available! For more information about this release, check out this topic.
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MMM-PIR does not shutoff sometimes



  • Hi
    I am using the PiR since beginning of my MM journey.
    But i‘ve Observed that the monitor stays sometimes on for many many minutes (timeout 120sec)
    What could be the reason?
    There is no light change or movement in the room.
    And I have played with the potentiometers in the PIR-PCB



    • What is a PIR Sensor? It’s Passive Infrared Sensor, that measures infrared light radiation from objects, that is: heat radiation.

    • Does a PIR sensor sense light change? No. But it can detect a light source if it heats up fast enough when it’s on. So it could detect an old lightbulb – if that lightbulb is in view – but probably not a cold LED.

    • Does a PIR sensor sense motion or movement? No. If you drag something through it’s field of view that is not emitting heat, the sensor won’t detect it.

    So, there’s probably something in its field of view that is emitting heat. A hot lightbulb, a radiatior, an animal, someone sitting there, even though that person seems motionless. If you’re watching it, it may be detecting you.

    Does it turn off after ~ 120 seconds if you really leave the room, close the door, stay behind the sensor? Maybe it’s not correctly set up or cables aren’t correctly attached? Or it’s a faulty PIR …



  • @doubleT said in MMM-PIR does not shutoff sometimes:

    • What is a PIR Sensor? It’s Passive Infrared Sensor, that measures infrared light radiation from objects, that is: heat radiation.

    • Does a PIR sensor sense light change? No. But it can detect a light source if it heats up fast enough when it’s on. So it could detect an old lightbulb – if that lightbulb is in view – but probably not a cold LED.

    • Does a PIR sensor sense motion or movement? No. If you drag something through it’s field of view that is not emitting heat, the sensor won’t detect it.

    So, there’s probably something in its field of view that is emitting heat. A hot lightbulb, a radiatior, an animal, someone sitting there, even though that person seems motionless. If you’re watching it, it may be detecting you.

    Does it turn off after ~ 120 seconds if you really leave the room, close the door, stay behind the sensor? Maybe it’s not correctly set up or cables aren’t correctly attached? Or it’s a faulty PIR …

    Thank you, i did not know this. This explains a lot, it could also be that its not corrent attached, so it could get the heat of the MagicMirror housing?!



  • Depends on position and deflective angle of the sensor. If you think there is nothing it should detect, try it out, leave the room, set a timer and check after 120 (+10) seconds.