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Flash .erase uf2 for ItsyBitsy M4 Express?
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Flash .erase uf2 for ItsyBitsy M4 Express?

by kmevans on Wed May 20, 2020 12:46 am

On the page https://circuitpython.readthedocs.io/en/5.0.x/docs/troubleshooting.html it mentions a file which I cannot find on the link https://github.com/adafruit/Adafruit_SPIFlash/tree/master/examples/flash_erase_express, and when I tried to generate it from the INO file I believe that I failed. Actually that was a two step process, but I'm not sure if the INO configuration is appropriate for the M4 board.

"1. Download the appropriate flash .erase uf2 from the Adafruit_SPIFlash repo."

Anyways - the reason is that I loaded a really simple code.py which seems to be preventing the drive from mounting. I was playing around with some rather large numbers and it seems like these math libraries don't yield time (e.g. CTRL-C can't interrupt execution of them), so perhaps this explains it. Maybe I should post this elsewhere as an issue, but I don't want to post here yet.

I can still get to the bootloader.

kmevans
 
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Re: Flash .erase uf2 for ItsyBitsy M4 Express?

by kmevans on Wed May 20, 2020 12:57 am

I found some files here https://learn.adafruit.com/adafruit-feather-m4-express-atsamd51/troubleshooting, and took a guess that "Trellis_M4_QSPI_Eraser.UF2" would work for the M4 express. It did, so I'm happy for today since I didn't have anything on the drive that wasn't on my computer. But I'm still wondering if I looked in the right places for this erase file. And where would I file an issue about CircuitPython related to this?

I posted to the feedback/comment link on https://learn.adafruit.com/introducing-adafruit-itsybitsy-m4/troubleshooting, and started a thread in the CircuitPython area.

kmevans
 
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Re: Flash .erase uf2 for ItsyBitsy M4 Express?

by adafruit_support_carter on Thu May 21, 2020 6:42 pm

If you were still able to connect to the REPL over serial, then this is the better way to erase the SPI flash:
https://learn.adafruit.com/welcome-to-c ... stem-20-24

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Re: Flash .erase uf2 for ItsyBitsy M4 Express?

by kmevans on Thu May 21, 2020 8:14 pm

Yes - that's a handy way but in this case a Python program written to code.py prevents CIRCUITPY from mounting, and also blocks me from the REPL. My guess is that bignums are interfering with the operation of the USB stack.

https://forums.adafruit.com/viewtopic.php?f=60&t=165589

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Re: Flash .erase uf2 for ItsyBitsy M4 Express?

by adafruit_support_carter on Fri May 22, 2020 1:02 pm

OK, yep, in your case I think that was your only approach.

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Please be positive and constructive with your questions and comments.