I'm designing a Raspberry Pi HAT that requires USB for debugging. The 40-pin GPIO connector that connects the Pi to the HAT doesn't seem to have any USB designated pins. I would like to use the USB port already located on the Pi to do the debugging but I don't know if that is possible. Would I need to include a USB port on the HAT itself or is it possible to use the USB port already located on the Pi?
The USB port is NOT available on the 40-ping connector!
If a USB serial is enought for debugging then you could add a USB-Serial chip like CP210x, CH340/CH341 or equal to the UART RX/TX pins, then you will get a USB serial on your HAT.