I’m working on a project with the pn532 that up until just recently was working pretty reliably with my implant, but now even though it still works well with some regular ntag216’s, all it does is light up the LED on the implant, it doesn’t actually capture the UID, as though the XSIID was only powering the light and not the transmitter. Has anyone else come across this issue with this combo?
Also, the implant works well with my phone still, so it is still transmitting at least
Only thing I can think of is that you’re right about it powering the light and not the chip. Iirc Amal has said elsewhere that the power harvesting circuitry gets priority over the chip so if there’s not enough power after powering the LED, then it wouldn’t power the chip.
check power inputs and make sure the voltage is up to snuff and there isn’t any extra loads on any GPIOs that might be dragging down performance… and also check mounts, nearby metal, and other forms of interference that might be new that will impact performance of the antenna
Interesting, I thought the chip supplied the power to the LED, but I knew there was a performance drop. The only thing that makes me doubt that is that the LED lights up quite brightly
oh that’s odd… hmm… has your code changed at all?
Nope, it’s still the same, and the program I’m using now just spits out any UID it finds, but I’m getting nothing from the implant, though my two ntag216’s work well with it. I thought maybe my data lines were shorted or something, but since the other cards work I’m doubtful of that
A quick update, all the continuity tests indicate that nothing is shorted, and the voltage reads as expected on the reader
Any other possible sources of interference or possibly power supply line noise?
None that I can find, the power supply cable for the arduino has a ferrite bead on it, so no interference there; There’s no large sources of metal near it or any other tag causing collision issues
I do however remember the instructions saying to use 90 degree angle connectors for the connections, while my wires are now soldered directly to the board, but I can’t imagine that would make that big of a difference, especially since the reader works on other tags
The wires are also routed in a way that brings them almost 90° off the board above the antenna anyways
Okay, I figured it out, sort of
I know how to fix the problem, but not really what caused it or why it was only the one chip
Basically, it was something to do with my computer’s usb port, upon trying a different usb power supply, the arduino is accepting my chip again and behaving as it should be
I don’t know why that usb port would stop only my chip from reading, especially since I’ve used it through there before, but I’m content to have my project actually working for now
Final (hopefully) update
It seems to have also been the cable somehow, using a different one I’m able to use the computer’s usb port
Though, the first cable did work on the other supply.
Seems like I had just the wrong combo of picky port and picky cable
You might want to double check your code.
I once found an “issue” where the script was Identifying the correct USB connecter reader in order to start the read, but it was attempting to read from a second reader, which was at another “usb port”.
That came from a mistypo on the reader-holding variable name, which triggered the library to try and fetch a new reader, and there was another device being picked up.
That would make sense, but the usb cable was only supplying power to the arduino, it didn’t interact with the code at all, the reader was wired directly to the arduino pins
uhmm… maybe the port was poorly grounded…?
the only other time I saw slightly similar behaviour was when installing wiretaps. If the job was poorly done you could have some weird side effects like that (although I strongly doubt you have a wiretap in your usb port. )
That I would believe, I think the cable was quite old and might have hand some connection or grounding issues
Well, I haven’t specifically checked, but I would guess I don’t too lol