Other RP2040 boards • Re: Help with custom RP2040 board

Thanks for your help so far

I'm not an oscilloscope expert, what should I see on XIN and XOUT?

I've used the recommended 12MHz ABRACON part, although re-reading my schematic and comparing it to the standard one, I do have pins 1 and 3 reversed - but this shouldn't matter, should it?

If using Picoprobe you need to be using an SWD debug tool like OpenOCD, not picotool. Your script shows picotool trying to control the device over USB.

So I'm using PlatformIO, I was developing this board on my bench using two Picos, one as the debugger and one as the placeholder for my board, checking all my peripherals/pins worked.


The current setup works to flash and debug the Pico, so I would expect it should work identically with my board, which is essentially a Pico. Ill read what you're referring to though to educate myself some more.

It's unfortunate that you didn't connect the RUN (reset) pin to anything, but maybe you can poke a wire at it to force a reset. Slow rising power supplies can cause the power-on-reset to fail and a manual reset then works.

I can just about solder a wire on (bridging the two adjacent GPIOs). This is OK to leave floating for normal operations, right? But here you're saying briefly short it to GND to cause a reset?

Just tried this, had no effect. My PSU is an AP2112K-3.3 which I'm manually turning on with the EN pin, and it has a 20us power-up time which should be fast enough?
Not-very-obvious board layout below, happy to share a KiCad file if thats of any use. Note ive swapped the Xtal pins 1/3 now in this layout

Its a 4 layer board with GND on the next inner layer, then 3v3 next (with a single trace connecting 1v1), then some unrelated components on the other side

Statistics: Posted by trullock — Wed Sep 10, 2025 6:28 pm

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