Feather M4 Uf2 firmware flash

[ashsk]

Hi,

I'm using Feather M4 for a lot of projects and I'm curious to know if I can flash the firmware over USB by just drag and drop of the .uf2 file? I understand that's how easy it is to flash the micropython scripts by copying the relevant files to the USB storage drive. I've already tried upgrading the bootloader using the Uf2, but I'm trying to find out if I could also flash my firmware similarly?

[dastels]

Yes, that's how you install the CircuitPython firmware. You copy a uf2 to the FEATHERBOOT drive. You can also use Arduino or PlatformIO.

Dave

[ashsk]

Perhaps my question wasn't clear enough. I meant can I write a C code and generate the binary file which is converted to uf2 format to flash on the FEATHERBOOT disk?

[dastels]

Yes. See https://github.com/Microsoft/uf2.

Dave

[ashsk]

I did take a look that. I actually followed the instructions and was able to generate a uf2 file from the Arduino LED blink example. When I copied it to the Feather M4 in the bootloader mode, the bootloading cycle happens and then nothing happens. The LED on pin 13 is supposed to blink but it does not.

[dastels]

To confirm a couple things:

The code works when uploaded directly from/by Arduino?
You copied the UF2 to FEATHERBOOT?

Dave