Working on a demo that uses some motion sensing, I’ve got three OpenPIR devices: https://www.sparkfun.com/products/13968 and they all behave inconsistently.
Setup:
Powered via 3.3 VDC, not using hookup guide example to measure, using DOUT to FPGA GPIO input.
3.3 VDC is direct from regulator
DOUT is connected to tristate input with PU resistor
FPIO VCCIO is same 3.3 VDC rail that OpenPIR is powered from
OSC is fully turned CCW
SEN is left in the middle (or thereabout)
Soldered down JST connectors: 455-1721-ND
Pre-made cable: 455-3151-ND
Observations:
Out of 10 power-cycles, a single module more or less does the following:
Works correctly: 1-2 times
Is incredibly overly sensitive and almost constantly triggers: 0-1 times
After power-up LED done blinking, registers no movement whatsoever: 7-9 times
This same behavior is observed across all three modules, tested with multiple cables as well. But I can literally unplug and re-connect the cable and observe different behavior. The startup sequence is the same each time and does not appear to falter.
3.3 VDC rail is stable and low noise.
I note that the datasheet for the devices call out 5 V typ. but able to work down to 3.3 V. Are there any known issues when running at 3.3 V?
I’m not able to easily connect these to a 5 V source to verify, but I can do that if needed.
YellowDog:
Have you tried going back to basics and using an Arduino Uno? You might do that first to confirm the sensor is operating correctly.
No, I don’t have any Arduino products available to me to test on. The problem exists even if I completely disconnect the OpenPIR output from the FPGA GPIO too, so the only issue is either with the OpenPIR module itself, or something related to power input to the module.
I also want to add a clarification.
When in the failed state of no motion detected, the LED on the OpenPIR never tuns on outside of the initial startup blinking. Conversely, when in the failed state of extreme sensitivity, the LED is on nearly all the time with brief flickering off as if its being re-triggered.
I can also set up a test with the analog output and provide scope captures if that is useful. I wanted to reach out here before I did that though to see if there were any known issues like this, especially since I see it on three different units.
Could be a defective sensor, you might try contacting the seller and explaining the defect and see if they can replace it with another. Don’t know about other sellers, but sparkfun has a need help? button on their website and that should get you to someone that can help with a replacement.
YellowDog:
Could be a defective sensor, you might try contacting the seller and explaining the defect and see if they can replace it with another. Don’t know about other sellers, but sparkfun has a need help? button on their website and that should get you to someone that can help with a replacement.
3 out of the 3 I ordered though? That seems like quite a low chance.
Come Monday I guess I’ll do some more testing. I was hoping to get some SparkFun tech support here rather than just outright return them (since this seems like the only avenue for support). If I find anything else I’ll report back here but would still love to heard from SF directly on the matter as well.
as citizens and volonteers involved in a project to count bicycle traffic along a cycle paths in Rome, Italy (to press public officers to improve and maintein urban cycle path network)
we have implemented a low cost traffic counter unit using your openpir.
We have already 5 units operating along streets, and we are planning to set up other 8 counter units.
We have already bought more than 20 “openpir” , but unfortunately, 10 stopped working just after few days, forcing us to test one per one before building new unit (see picture attached).
After Boot up led sequence (always ok), faulty sensor can’t recognize ostacle anymore after few days working properly.
Voltage supply is between 4 and 5v.
We are going to share our project all over the world, helping other people following same goal. But we can’t promote a PIR sensor with so high faulty percentage.
I’m waking this thread back up rather than starting a new one.
I sent an email to SparkFun, and the auto-response said “All our technical support is handled through our forums” so here I am again hoping to get some additional information on the issue.
I have 3 OpenPIR units, and they all behave very strangely. The target application supplies them with 3.3 V, but once failed, I see the same issues at 5 V so it is not related to V supply.
When installed in the application, a PIR sensor will run fine for 10s of minutes up to a couple of hours, after which time it completely stops responding to motion. Power cycling does not fix the issue. However, having been in storage for 6 months, all 3 units have returned to a functional state. These again only function for 10s of minutes up to a couple of hours and then they hit the failed state.
I’ve created a jig that I can plug a unit in to for further examination. On a “failed” unit, I see absolutely no activity on the “A” analog output. I have two failed units that both ran successfully for most of a day before stopping and both of them show a flat ~2 V line on my o-scope. The 3rd unit has only been used briefly and is still functional. Its output on the analog pin is what I expect when observed and it asserts its output correctly still.
Are there any issues where the analog output ends up completely flat? I don’t mind doing part replacements, mods, or further testing, but it would be nice to have these three units working since its just a one-off demo and I don’t want to have to buy 3 more at this point. Thanks for any help you can provide!
