Hardware Issue: Problematic routing of USB differential pair! about crkbd HOT 4 OPEN

I hope you understand the severity of this issue. Depending on the USB standard, routing of D+/D- is Critical for a functioning device.
Read this guide: https://resources.altium.com/p/routing-requirements-usb-20-2-layer-pcb.
A very comprehensive guide can be found here https://www.ti.com/lit/an/spraar7j/spraar7j.pdf?ts=1712482750918&ref_url=https%253A%252F%252Fwww.google.com%252F

I measured the trace length of D- is approximately 100mm or ~ 4 inches.

If you use USB fullspeed spec, the critical length 10% limit is exceeded, but it is within the 25% length limit, this might work but is not ideal.

For USB high-speed spec, you are exceeding the 10% length limit by a factor of 10. This means, if you use USB high speed, the board is out of spec and probably not working correctly!

Best

from crkbd.

Not sure if this is related but I notice that if I leave mine idle on occasion I will have to unplug to get keystrokes sent, but all on board functions work properly. Or maybe this is a qmk issue and I need to fix some setting.

Edit might be the USB_SUSPEND_WAKEUP_DELAY. I will report back when I flash the firmware later.

Later: that has resolved the wake up problem, I'll submit a PR to update the firmware in your repo.

On another note now I randomly see 1 or 2 LEDs shutoff.

from crkbd.

Thank you for sharing. I keep to investigation too.

from crkbd.

I'll add this here since that wake change I haven't had an issue with a direct usb connection to the laptop. However through my level 1 KVM I still experience this issue, but appears to be only on my work mac and not my Linux pc.

I will keep debugging but leaving this here since it could be related to the usb spec constraint pointed out.

from crkbd.