I decided to make a pcb based on the atsam3x8e (microcontroller used in Arduino Due). For the design I copied most of the layout that I found on this site and looked at the official Arduino Due schematic as well but decided that I didn't need everything. This is the schematic that I made and the pcb:

enter image description here My schematic enter image description here enter image description here

The problem is that my laptop doesn't see the "Arduino Due / atsam" when I connect the USB to my pc with a USB cable (with data lines). I understood that the chip chips with the SAMBA bootloader in ROM and that it should be programmable via native usb connection to the chip.

I supply 3V3 with a bench power supply. Then I tried to follow the checklist for this microcontroller: checklist. All voltages seem to arrive on the chip. VDDout makes a 1.7 voltage as it should. I have a clocksignal on my 12Mhz crystal. I don't have a clock signal on my 32khz crystal but when measuring on an official arduino due I also didn't see a clock signal here so I guess this oscillator isn't always on.

I made some wire patches: decoupling cap were not ground referenced and one oscillator pin of 12 Mhz wasn't connected.

Any ideas on how I could further debug this?

  • check for unwanted solder bridges ... you have what looks like stray bits of solder on the board
    – jsotola
    Sep 15, 2020 at 18:10
  • did you solve this issue? I'm having a similar issue with my atsam3x8e design where windows show it up in device manager as an "Unknown USB Device (device descriptor request failed) and I can't work out why it won't show up as a com port. I verified that the chip is up and running fine by programming it over the TX and RX pins with a USB to serial converter. This might be a good place for you to start debugging your design, although you will have to add a 2 pin header connected to the TX&RX pin to your design. Dec 2, 2020 at 21:49


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