spookeo
Posts: 5
Joined: Fri Sep 17, 2021 10:09 am

Custom RP2040 Board - Unknown USB Device (Device Descriptor Request Failed)

Fri Sep 17, 2021 10:13 am

Hey all,

I've designed a custom RP2040 PCB based on the minimal guidelines but I cannot get it to be recognized by Windows.

Here are photos of the schematic and board,

https://imgur.com/a/uOugVMn

I'm sure you'll need more information but it would be great to get some help with this as I'm really quite stumped.

Note - I have tried to use Picoprobe and I was able to connect to the board but not sure where to go from there.

Thanks!
Last edited by spookeo on Fri Sep 17, 2021 10:34 am, edited 2 times in total.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 29678
Joined: Sat Jul 30, 2011 7:41 pm

Re: Custom RP2040 Board - Unknown USB Device (Device Descriptor Request Failed)

Fri Sep 17, 2021 10:23 am

Can you uploads the images somewhere, and link to them instead of trying to attach? There is an relatively small limit on embedded images on the forum.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Working in the Applications Team.

spookeo
Posts: 5
Joined: Fri Sep 17, 2021 10:09 am

Re: Custom RP2040 Board - Unknown USB Device (Device Descriptor Request Failed)

Fri Sep 17, 2021 10:32 am

jamesh wrote:
Fri Sep 17, 2021 10:23 am
Can you uploads the images somewhere, and link to them instead of trying to attach? There is an relatively small limit on embedded images on the forum.
Oh right no worries, I've uploaded them all this imgur album,

https://imgur.com/a/uOugVMn

Lobo-T
Posts: 23
Joined: Fri Jan 22, 2021 10:52 am

Re: Custom RP2040 Board - Unknown USB Device (Device Descriptor Request Failed)

Fri Sep 17, 2021 10:40 am

Your R3 and R4, the resistors in series with the USB datalines are marked as 27k in the schematic. They should be 27 Ohm.

spookeo
Posts: 5
Joined: Fri Sep 17, 2021 10:09 am

Re: Custom RP2040 Board - Unknown USB Device (Device Descriptor Request Failed)

Fri Sep 17, 2021 10:51 am

Lobo-T wrote:
Fri Sep 17, 2021 10:40 am
Your R3 and R4, the resistors in series with the USB datalines are marked as 27k in the schematic. They should be 27 Ohm.
Oh my, erm, good spot! :shock: I'll give swapping them for the right resistance a try!

Lobo-T
Posts: 23
Joined: Fri Jan 22, 2021 10:52 am

Re: Custom RP2040 Board - Unknown USB Device (Device Descriptor Request Failed)

Fri Sep 17, 2021 11:06 am

spookeo wrote:
Fri Sep 17, 2021 10:51 am
Oh my, erm, good spot! :shock: I'll give swapping them for the right resistance a try!
Guess why the solder on my R7 and R8 looks a bit "blobby":
Image

(Copy/paste error when editing the BOM :roll: )

hippy
Posts: 10761
Joined: Fri Sep 09, 2011 10:34 pm
Location: UK

Re: Custom RP2040 Board - Unknown USB Device (Device Descriptor Request Failed)

Fri Sep 17, 2021 1:44 pm

spookeo wrote:
Fri Sep 17, 2021 10:13 am
I've designed a custom RP2040 PCB based on the minimal guidelines but I cannot get it to be recognized by Windows.
Windows is far less forgiving than Linux when it comes to USB and device drivers and I would always recommend proving it works with Raspberry Pi OS or Linux before even trying with Windows.

Proving that it works under Raspberry Pi OS or Linux will be hugely beneficial in figuring out why it doesn't work under Windows when that is the case.

spookeo
Posts: 5
Joined: Fri Sep 17, 2021 10:09 am

Re: Custom RP2040 Board - Unknown USB Device (Device Descriptor Request Failed)

Fri Sep 17, 2021 3:24 pm

Lobo-T wrote:
Fri Sep 17, 2021 11:06 am
spookeo wrote:
Fri Sep 17, 2021 10:51 am
Oh my, erm, good spot! :shock: I'll give swapping them for the right resistance a try!
Guess why the solder on my R7 and R8 looks a bit "blobby":
Image

(Copy/paste error when editing the BOM :roll: )
Hah, glad I'm not the only one then.. will report back once I've changed them out!

spookeo
Posts: 5
Joined: Fri Sep 17, 2021 10:09 am

Re: Custom RP2040 Board - Unknown USB Device (Device Descriptor Request Failed)

Sat Sep 18, 2021 2:02 pm

hippy wrote:
Fri Sep 17, 2021 1:44 pm
spookeo wrote:
Fri Sep 17, 2021 10:13 am
I've designed a custom RP2040 PCB based on the minimal guidelines but I cannot get it to be recognized by Windows.
Windows is far less forgiving than Linux when it comes to USB and device drivers and I would always recommend proving it works with Raspberry Pi OS or Linux before even trying with Windows.

Proving that it works under Raspberry Pi OS or Linux will be hugely beneficial in figuring out why it doesn't work under Windows when that is the case.
Thanks for the advice, I only tried Windows as I don't have a Linux or Pi OS device handy, I did at first try 18ohm resistors as that's all I had in the same package size, but yeah not even that worked..

So for testing purposes, I had to fit some larger package size 27ohm resistors which then did work! :geek:

Image

I was able to access the flash via BOOTSEL and also communicate by serial COM with Circuit Python and Thonny, and managed to do a blink test with an attached LED.

Image

Thanks all for spotting my error :P

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