Are my GPIO's working properly ? [Solved]


#1

Hi there, so ye something has definitely gone wrong big time with my axoloti. Did some soldering and de-soldering work on the pins PA3 up to the GND next to PA5.
Had a poke about with a multimeter to check before attempting to re-attach header pins, with the positive probe on the VDD connection and the negative probe on the inputs, and ive found none of the Inputs seem to be bridged anywhere with each other, but there is current flowing from the VDDA port i used and the one next to PA5 to all the inputs on the board,and also to all the GND terminals too.
Then in terms of the patcher all inputs are showing the same thing and cannot be moved, which i have included a picture of. Was just wondering if anybody knew would has gone wrong for sure, and what if anything can be done to remedy the situation, its an Axoloti core v1,2 if that makes any difference.
Thank you for your time!


#2

Could you check with a multimeter: remove power from the Axoloti Core, put it in diode test mode, red probe to GND, black probe to any GPIO. The reading should be 600 to 900mV for any of the PA..., PB..., and PC... GPIOs. An "infinity" readout indicates the circuit board track between the gpio pad and the processor is broken.
Analog inputs that are not connected to a source tend to track the previous input.
Does touching the GPIO pads with your finger show any response in your test patch?


Troubleshoot AxoControl connection
#3

ok have tried that, all of the GPIO respond as expected, a couple of them only a couple of mV lower but thats ok.
when touching PC0, PC0-PCR respond.
same with PA0-7 when i touch PA0, oddly when i touch PA7,6 & 5 also respond
what does this mean ?


#4

If GPIO inputs respond to touching with your finger, and they show a 600 to 900mV diode drop to ground, I can't see a reason why they would not work for other inputs.
What made you conclude something is broken?


#6

Hi sorry i was expecting them to be reading flat as so far whenever i have used any gpio its been when there is something attached, then when i multi metered it i thought there shouldn't have been any current flowing so thats what made me think i had messed up something with the soldering!