PIR discussion notes

Is it possible to decrease the power to a PIR sensor either through downgrading or programmatically?

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I recently purchased and configured two motion sensors on a Raspberry Pi 3B model. I am very excited as I am getting a reading but the sensors are very responsive. Is there a way to narrow the infrared beam or to decrease the power to the sensors so that they aren’t so jumpy?

I am very new to all of this… so apologies if I am off with my words.

Thanks yougpiopythonshareedit  follow  close 1flagedited 23 mins agoMilliways45k1919 gold badges7575 silver badges147147 bronze badgesasked 1 hour agomcroteau111 New contributor

  • 1Most of the inexpensive PIR modules come with a pot to adjust sensitivity and only output a go/no go level. They are fitted with a Fresnel lens to increase the field of view and sensitivity. – Milliways 22 mins ago 
  • @mcroteau, Welcome and nice to meet you. Ah, let me see. As far as I know the old types of hobbyist PIR sensor are too sensitive, so they always stay false positive. It is a bit tricky to adjust the sensitivity. Perhaps you can try the new generation of digital PIRs which are as cheap, but easy to adjust. You can find more details in my Penzu reading and testing log: penzu.com/p/d65553dc. Happy learning. Your sincerely. Cheers. – tlfong01 17 secs ago   Edit   

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1 Answer


I don’t know of any practical way to “narrow the beam”, and that would likely make the sensors more, rather than less, “jittery”.

Maybe share what sensor you’re using?? Does it have any documentation? They all have differences, and it’s difficult to provide a pat answer to your question.

Two suggestions:

  1. You might try doing some research first, maybe after reading this, and then editing your question.
  2. In general, I think you should consider the idea of integrating the sensor output over time. You can do this in software. You will have to learn to discriminate “false alarms” from real detection events – i.e. a motion detection event that represents a valid alarm. Integrating the output over time is a place to start.

shareedit  follow  flag answered 4 mins agoSeamus8,48211 gold badge1010 silver badges2929 bronze badgesadd a comment


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