Wanted: Porting guide / developer guide

[Damien]

I did just notice that ST has publish STM32Cube for the F1 family of their MCUs.

Yes there is a new version of the Cube HAL. I haven't looked at it yet but I will upgrade when I get time and then maybe the F1xx is easier to support.

[bboyd]

Hi All.
I'm a complete newbie to Python, microPython, so apologies if this question is off topic

I have an STM32F217 prototype board about to hit the bench very shortly. The processor is footprint compatible with the STM32F4x7 device, so it may be relatively simple port microPython to the F217 as most of the STM devices currently supported are in the F4xx range.

Are there any specific processor hardware requirements (MMU, FPU etc) that would mitigate against porting to the F217.

I'm reasonably familiar with the STM32CubeMX (and thus the stmhal), so I'd be prepared to have a go at a port provided there was some indication that it would be possible.

[dhylands]

It should definitely be possible.

I'd recommend starting with a part that has 512K flash. The amount of RAM depends largely on what you need to do on it and the sized of the flash blocks used to make up the file system.

I know that the current stmhal build with the default options no longer fits on the ESPRUINO PICO (384K flash F401).

You should be able to target smaller parts, but it will be more work.

[bboyd]

Thanks for the answer - that gives me a bit more of an incentive to move forward. The prototype board we have coming has a microSD card slot, so presumably the file system can reside on the SD card rather than in FLASH?

[dhylands]

MicroPython supports external sd cards. It may take a bit of effort to turn off the internal filesystem. It should be doable, I'm just not sure that anyone has done it before, so it probably won't be as simple as turning off a few config options.

[pythoncoder]

To clarify you can mount an external flash drive in the filesystem, where you can access it in addition to internal flash. You don't have to disable the internal flash to use it.