pyboard doesn't show up as USB flash device on Windows 10 machine

The official pyboard running MicroPython.
This is the reference design and main target board for MicroPython.
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Target audience: Users with a pyboard.
Gordon_Hardman
Posts: 61
Joined: Sat May 03, 2014 11:31 pm

Re: pyboard doesn't show up as USB flash device on Windows 10 machine

Post by Gordon_Hardman » Thu Aug 09, 2018 5:27 pm

It is definitely a Windows issue, but there is an interesting Pyboard tie-in. Now all of my Windows PCs will not recognize the V1.1 Pyboards. Except that the V1.0 Pyboard is okay on two of the machines- but has the double COM port issue on PC #2.
Also, since moving the V1.1 boards around my digital camera (which has worked fine for years) is suddenly not recognized on USB either.

Googling suggested several approaches, none of which worked:
1. Disable then Enable the USB root hub.
2. Uninstall/reinstall the USB hub driver.
3. Disable the USB selective suspend in the power options.

It seems like the disease is spreading to other USB devices. Some USB flash drives are now not recognized on some machines. It is probably just a coincidence, but all of the trouble seems to start when I plug a V1.1 Pyboard into a machine. There must be some timing/handshake that is getting "off" and leaves the USB device/machine combination unstable. It is not just the device, I took my digital camera to a fourth (uninfected AFAIK) machine and it showed up fine. I then brought it back to PC #2 where it was previously not recognized, and it showed up just fine. It appears from this that there are two interlocked issues- one in the Host, and one in the Device. Taking a sick device to an uninfected host "cures" it, seemingly.

I have plugged the V1.1 Pyboards into 3 PCs, all of which now exhibit the problem. I have not plugged them into the 4th machine, and it seems stable.

I am pretty much dead in the water with the V1.1 boards- I can't even get DFUSE to recognize them any more. I suppose I might try them in the 4th machine with them being in DFUSE mode from the start, although I am reluctant to connect them to that machine at all.

Gordon_Hardman
Posts: 61
Joined: Sat May 03, 2014 11:31 pm

Re: pyboard doesn't show up as USB flash device on Windows 10 machine

Post by Gordon_Hardman » Mon Aug 13, 2018 6:11 pm

On reflection, the problem must be with the USB peripheral on the ST chip. This is because the USB device does not show up in DFuse or as a composite memory/com USB device. I have now verified this on 5 PCs, 4 running Windows 10, and one Windows 7.
I remember reading somewhere that the Pyboard could not be bricked, but somehow I seem to have done it on two of them!

chrismas9
Posts: 66
Joined: Wed Jun 25, 2014 10:07 am

Re: pyboard doesn't show up as USB flash device on Windows 10 machine

Post by chrismas9 » Thu Aug 16, 2018 1:17 pm

Saying it's two dead STM32's doesn't correlate with the misbehaving flash drives and camera.

1. If you reboot the PC's do the other devices work on all PC's?

2. To determine whether it's a Windows software issue try booting from a run from CD Linux distro. I the pyboards work you may have a driver problem. If they don't work under Linux you may have damaged the USB port on either the PC's or pyboards.

3. Do any of your PC's have 2 pin power plugs? If so the chassis and USB cable are biased to half mains voltage by EMC capacitors, usually between 50-60V or 100-120V. The current is low but can spark and damage IC inputs.

The dual com port is a mystery. I have used lots of different boards running MicroPython with all releases of Windows 10 and I have never seen it.

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