half a USB problem on STM32F401
Hi
I designed a replacement pcb for a keyboard of mine with an STM32F401(RCT6).
I used the QMK framework to make a firmware which I can download via DFU perfectly fine (I also uploaded it and checked it against what I downloaded..). The PC detects the keyboard when running the firmware, but can't connect (USB errors -32 and -71). I tested the firmware on my Mode Envoy which uses the same exact chip and it work, so naive me rules out defective firmware.
Here is the link to my kicad project: https://github.com/zegonix/custom-cycle7-pcb
So far I tested the supply voltage, the reset signal and the clock as well as the usb signals. The supply voltage and reset signals seem perfect to me, the clock is a stable 12 MHz with 900 mV amplitude (can't remember the offset, but seemed reasonable) and the usb signals have a little overshoot, but seem good enough. It's only full speed (12 MHz) after all.
Does this issue seem familiar to anyone? Or any pointers?
Best regards,
blap