I’ve been working on a rather maddening project lately, and after extensive testing and research, I’m about ready to throw in the towel and move to a different platform.
I have a common PIR sensor (picture below). When connected to an Arduino UNO it works perfectly. Triggers when it should, and stays quiet the rest of the time.
As soon as I move this sensor into an analogous Argon project - using the exact same connection leads - it goes nuts. The PIR is getting triggered by something on the Argon on a regular interval. It’s a very regular pulse. I’ve tried filter caps (10uF, 1uF, 0.1uF), ferrite chokes, and nothing stops this when the project is running on the Argon. If I move the sensor back to the Uno - with the same connection leads - it’s fine. So I know it’s not anything with the sensor itself.
Code? In addition to the stock example code provided by numerous online sources, I have combed the web for various sketches (including this site) to build in ways to adjust the sensitivity. Up to 6 sketches, with different approaches, all result in the same thing. The only thing that seems to vary is the frequency of the trigger. Sketch A might be 80 seconds, while sketch C is every 60. One outlier sketch was every 5 seconds.
Environmental factors? Turned off things like LED lights and such, but again - if the sensor works on the Uno in this environment, why would that matter? In any case, I’ve noticed no other devices causing this interference. I even took the project down to the basement to see if a complete change of venue would provide any insight. Same issues. Everything points to something on the Argon itself.
Power? I’ve tried LiPo, USB power from my laptop, and a USB wall adapter. No difference.
I know PIRs are notoriously finicky, but since I have a working project on Uno, I don’t see why the Argon is having so much trouble on this. Also tried a second Argon - same thing.