SAMD21 Xplained Pro support

[riegaz]

Is this Atmel Evaluation Kit supported? I was not able to get it going.

Any help is welcome.

[ladyada]

not yet but it ought to work with internal storage (unless it has a SPI flash on it?)

[riegaz]

I didn't get it working by flashing any bootloader onto it. It has a serial flash installed but I would prefer it working qith the internal storage.

[ladyada]

ok start with the UF2 bootloader, you can probably look at the Trinket M0 or Feather M0 Basic for inspiration :)

[tannewt]

Check out this guide about adding new boards to CircuitPython: https://learn.adafruit.com/how-to-add-a-new-board-to-circuitpython

[barawn]

I've gotten this working (although I just grabbed USB VID/PIDs, so don't ask for the binary :) ). The UF2 portion is painless - just copy over a board_config.h from the Feather M0, change LED_PIN to PB_30 (and keep in mind it's inverted, so it'll be opposite whatever the Feather's does), change CHIP_VARIANT to SAMD21J18A, and build it.

The CircuitPython part requires fixes in the asf4 repository (this has an open pull request to fix it, should be merged soon I imagine) and the samd-peripherals repository (already fixed in master, not updated in circuitpython master).

Once that's done creating a board with CHIP_VARIANT = SAMD21J18A builds fine. The SPI flash is an AT25DF081A, on PB22/PB16/PB23/PA13 (MOSI/MISO/SCK/CS), so just update those in mpconfigboard.mk/mpconfigboard.h.

[glucee]

@barawn can you share a bin file for that.

[tannewt]

@barawn Feel free to mention me on anything pending that still needs to be reviewed. I can provide a USB VID and PID too. So, feel free to make a PR and we can sort things out there.

[dhalbert]

Closing due to no progress. If anyone wants to do a PR that would be fine.