Feather 32u4 Bluefruit LE Windows 10 Device Descriptor Reque

[mjmeans]

This unit ran fine until now. Testing with example programs like blinky and a few others. Then stopped resetting. Windows Device manager reports Device Descriptor Request Failed. Strangely, the last sketch I uploaded was still working. Just couldn't connect again from Windows.

When attempting https://learn.adafruit.com/adafruit-fea ... e-recovery it entered DFU mode. I uploaded the Adafruit Bluefruit LE 0.8.1 firmware (including factory reset). The reported advertised name returned to default instead of the one I had set, so this surely worked. But Windows still reports Device Descriptor Request Failed when I plug it in.

I've tried different USB ports with no luck. Again, this feather worked fine on this PC for several hours while I was playing with different sketches and interfacing to a feather motor. Another feather (nRF52) also works fine on this USB port.

From BlueFruit Connect app:
- Software Revision: 0.8.1
- Firmware Revision: S110 8.0.0, 0.2
- Hardware Revision: QFACA00

[mikeysklar]

Thank you for verifying your cable / USB port are good by testing with another board.

I think the user program on your Feather 32u4 might have crashed and needs a carefully timed reset press during upload for the port to be found.

I'm having problems with COM ports and my Itsy/Feather 32u4/M0
Theres two COM ports you can have with the 32u4/M0, one is the user port and one is the bootloader port. They are not the same COM port number!

When you upload a new user program it will come up with a user com port, particularly if you use Serial in your user program.

If you crash your user program, or have a program that halts or otherwise fails, the user COM port can disappear.

When the user COM port disappears, Arduino will not be able to automatically start the bootloader and upload new software.

So you will need to help it by performing the click-during upload procedure to re-start the bootloader, and upload something that is known working like "Blink"

There are some other variations of USB discovery that can happen.

https://learn.adafruit.com/adafruit-fea ... ather-help

If the above does not help please paste in your full specific error message and we can try something else.

[mjmeans]

The link you provided didn't go into any details on what the "click during upload" process was referring to. However, after a google search, I found that the section "Manually bootloading" on page https://learn.adafruit.com/adafruit-fea ... rduino-ide using the Blink example immediately above this section resolved the issue.

Thanks.

Perhaps the FAQ could be updated to point directly to the click during upload procedure and refer to a "Device Descriptor Request Failed" error reported in Windows Device Manager. Just to save someone else 15 minutes of searching

[mikeysklar]

Good point. FAQ updated.