General Question: How Can You Control the MicroPython Entrypoint

[jrpear]

Hi all,

I'm getting a grip on the MicroPython project as a whole, and I'm finding the REPL very pleasant to work with (on a NUCLEO-F767ZI).

Eventually every project will have to go from the REPL to main.py stored in flash though if it's going to work across power cycles etc. I see you can compile custom modules into the MicroPython image, and therefore get the system to the point where upon boot you can connect to the REPL and just run import main; main.run().

But there's still the last 10%, and there is my question. Do you know how can I can invoke e.g. main.run() automatically as the entrypoint of my program, in place of the REPL?

Thank you,

Jack

[davefes]

All ports that I have worked with so far automatically run boot.py and then main.py on power cycles ... EXCEPT one I am working on for the STM32F723VGT6. So, I am interested in the outcome!

Try Google micropython _boot.py. I will read through them as well.

[davefes]

Maybe, https://github.com/orgs/micropython/discussions/15292

[jrpear]

Yes, that web search got me to the boot sequence docs which has me on the right track. Wouldn't you know it, one of the key files is indeed called main.py. Looks like I need to use mpremote as well to get the files on the board as they cannot be compiled into firmware.elf. Hopefully it works without any trouble on my board. Thanks Dave!

Jack

[davefes]

Thanks for the link:

_boot.py¶

This is an internal script frozen into the MicroPython firmware. It is provided by MicroPython on many ports to do essential initialisation.

I'll ask the author if that was done on the firmware I am trying to run.

[peterhinch]

In most projects there is no need to use the compiler. Assume you have a project file my_project.py which, in development, is run with

>>> import my_project
>>> my_project.run()

To auto-run create a file main.py containing

import my_project
my_project.run()

Ensure main.py and my_project.py are copied to the Flash drive on the device and reboot.

[jrpear]

Sounds like main.py is the key. Thanks Peter.

Jack