PIR Sensor: false positive detections
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Hi @zoltan - I was reviewing your tutorial. Really good documented. I have a question about the wiring drawing you shared. I’m new to it and dont understand everything. But I’m a fast learner
In your drawing you added a couple of symbols. I guess these are resistors and filters, right?
Numbers 1, 2 and 3 look similar, only with a diffrent capacity. Is that a Capacitor?
What are 4 and 5? Is that a conductor? What capacity is here needed?
And number 6, not sure. Is that a RND or a resistor?
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@mz-ber If you remove the resistor completely without any replacement the sensor won’t work any more.
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Didn’t I said, I’m not an electrician?
It is not a step-down/up … it is called Pull-Up, resp Pull-Down.
Please see here for detailed (german) explanation: https://www.elektronik-kompendium.de/sites/raspberry-pi/2006051.htm -
@thgmirror Yep, that is what I’ll do next. Already ordered a starter kit with resistors, inductors and capacitors.
I also noticed, even if I added the ferrite beat, that the sensor recevied every minute excact on the second a signal
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@thgmirror said in PIR Sensor: false positive detections:
It is not a step-down/up … it is called Pull-Up, resp Pull-Down.
Are you dealing with 3D printing? Just asking, because step-down converters are quite popular for modding cooling fans in that hobby
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@fozi no, currently no 3D-printing, but may be in the future:-)
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@mz-ber
Apologies for the late response
1, 2 and 3 is capacitors yes
4 & 5 is inductors or coils. The rule is a Capacitor conduct high frequency but block low frequency. The coil or inductor is doing the opposite, and conduct low frequency but block high frequency. The whole idea is to short circuit any spikes on the power line as well as the data line to ground. This is quite a big low pass filter and you can make it smaller with less components.
Remove 1
Leave 4 & 2
Replace 5 with a wire6 is a resister yes. 10 Kilo Ohm 1/4 watt is perfect
The coils you can strip out of an old circuit board. If it looks like a wire wind coil and it measure less than 3 ohm then its perfect
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@mz-ber
The controller board with the low pass filter
