Arduino for STM32

Hi !

Happy to see this forum again.

I plan to migrate my USB MIDI interface project to the "official" STM32 kernel, even if the current code works perfectly.
https://github.com/TheKikGen/USBMidiKliK4x4
BUT, after an unsuccessful attempt, I realized that there are significant differences and compatibility issues between the two cores, especially on USB I2C, and boards support.

As the Team recommends migration, is there a cartography of the functions covered by one and the other in order to estimate the effort required (and above all not to underestimate it !!!)? Is there a migration guideline somewhere or experience feedback ?

Hi TheKikGen

Nice to see you again.

I'm not aware of such "map".

The STM32 core follows standard Arduino API as far as possible some API extensions have been added but always trying to keep Arduino compatibility.

On the official core you will miss the whole "USB Composite library".
There was a thread started by Arpruss (maker of the library) about implementation here -> viewtopic.php?f=39&t=56
I don't about the current status.
As Frederic wrote the official core is based on "standard Arduino API" so without special libraries. This is a big difference between the cores. Rogers core is far more STM32F1 specific (with all those super special addons/libraries/DMA hacks) , but less compatible to the standard API.
But I2C should be compatible.

Edit: It's really interesting, that there was no real intention from official Arduino side to implement USB Host at least at a library:
https://www.arduino.cc/en/Reference/USBHost
USBHost ist Due only (not Zero!) and the last edit was somewhere 2018.

one can probably use the 'official' usb libraries, think there are quite some examples, HAL & all
i'm not sure if that is part of the Cube MX install etc