Support for M5Stack devices

[scarolan]

This feature request is for CircuitPython support on M5Stack devices like the Core, Stick, Atom and Stamp:

https://m5stack.com/

[dglaude]

Technically, ESP32 are not supported (anymore, since version 3.0?) by CircuitPython. The USB is not native and then it can not support emulating mass storage to expose CIRCUITPY drive. (This is not the case for ESP32 S2 or S3).
Practically, it would be up to the vendor of M5Stack to make the porting and propose a pull request with the support.

[tannewt]

This depends on: #1629

Note, we've never had ESP32 support. We did support ESP8266 early on but never the 32.

[steveatinfincia]

I have most of the M5Stack devices and I've been playing around with the circuitpython source tree to see if it will run on one of them.

I'm using ports/espressif/boards/adafruit_feather_esp32_v2 (a regular esp32, which #6613 suggests can at least run to some extent) as a starting point, however I'm not sure what the development workflow for these non-usb devices would be, is circuitpython-firmware.bin intended to be written to a particular flash offset using esptool.py?

[jepler]

Yes, the firmware is to be loaded at 0. Typical esptool commandline:

esptool.py --chip esp32 -p /dev/serial/by-id/usb-1a86_USB_Single_Serial_5479024009-if00 -b 921600 --before=default_reset --after=hard_reset write_flash --flash_mode dio --flash_freq 40m --flash_size 8MB 0x0000 build-adafruit_feather_esp32_v2/firmware.bin

I don't know the details of the M5Stack. Right now the Feather ESP32 V2 is the only board we have with the ESP32. It has 2MB PSRAM and 8MB flash. I was trying to get the Feather ESP32 V1 (no PSRAM, 4MB flash) working but it just boot loops, so there are more problems to find.

[askpatrickw]

M5 Related: I just today received an M5 Stamp C3 which I plan to do a board definition for next week.

[steveatinfincia]

The Core 2 works here, took some time to track down the cause of the reset but I just needed to prevent reset_all_pins() from resetting pins 7/8, which are psram data pins 0 and 1 on this device.

[steveatinfincia]

Almost everything working on Core 2, including the LCD, speaker, the green LED, vibration motor, internal I2C, and the grove connector.

The LCD on this device is an ili9342c, which is similar to ili9341 but has a few extra initialization commands.

The power management chip on this device is in charge of almost everything, even the green LED, the buttons and the vibration motor. It also supplies power to the speaker, the LCD, and the external ports and has to be initialized before any of those can be used.

I still need to move some of this code down to C so the basic stuff is properly set up in board_init().

[tannewt]

Nice work @steveatinfincia !

[ladyada]

neat!

[scarolan]

Wow this is great. I have an M5stack Core 2 AWS edition, would love to try CircuitPython and the atecc library with the secure chip:

https://docs.circuitpython.org/projects/atecc/en/stable/

[steveatinfincia]

I'm getting my core2 branch ready to submit a PR, still fighting with the occasional freezes (I2S, might be a coincidence), but all the major stuff seem to be resolved. Since I started working on this, other contributors have been merging fixes and improvements that made some of the little changes I was making unnecessary, so thank you for that everyone :)

@scarolan They don't provide a schematic for the AWS model so it's hard to tell but I believe the crypto chip is the only difference between it and the Core 2. The M5Stack Arduino libraries don't differentiate between them so that's a good sign.