Troubleshoot AxoControl connection

[bigpig]

Hey everyone! This is kind of a soldering/electronics-related question, not necessarily specific to Axoloti, but I figured this may be a good place to start looking for help.

I recently ordered the AxoControl DIY kit to connect to my core board. Following the instructions I soldered all the parts on the board. When I connect the AxoControl to the Axoloti via the 40 pin interface, the Axoloti core no longer powers on. The axoloti core still powers on when I disconnect the AxoControl.

I started troubleshooting by testing the connectivity between the pins on each side, using the continuity test function on a multimeter. It seems like there is no problem there. This is my first soldering project, and I know my soldering here isn't the best (pics attached), but I don't know if the quality of my soldering is the problem.

So looking for other issues such as unwanted connections... I found something that does not make sense to me, namely the pins for PA2-PA7 (the pot controller pins) seem to be connected when using the continuity test. I can't think of any reason why they would connect, but maybe it is by design...

Does anyone have any suggestions of things to try to diagnose the issue?

Many thanks!

[jaffasplaffa]

Hello

Well I am no expert on soldering and my own Axoloti boards looks A LOT worse than yours.... But mine works, only 2 of the LEDs that doesnt work.

I think you should recheck some of your solderings. Maybe there are some short cuts. Some of the soldering on the 40 pinheader looks "interesting". TO me the pinheader was a BIG challenge. If you heat it to much it will just melt and the pins will fall out..... There are many things that coulfd go wrong there..

[MrBim]

Are my GPIO's working properly ? [Solved]

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?

You might find this useful.

[johannes]

This looks like a solder bridge:

and those pins correspond to GND and VDD, bridging these will indeed black-out the Axoloti Core.

Tools | Adafruit Guide To Excellent Soldering | Ada...

[bigpig]

Thanks to all who chimed in! As @johannes suggested, there was indeed a short circuit between GND and VDD. However, the short was not in the pins, but somehow in the solder joints of the buttons. Desoldering and re-soldering the buttons fixed the issue and everything works perfectly. I was able to figure it out thanks to a friend who is much more of an expert in electronics and circuits - everyone should have a friend like that!