Originally Posted By: Eogund
Ok, I see my mistake, I did not tried to launch Joyloader while in bootloader mode (a little difficult, you only have a few seconds after manually restarting the device). Working OK now.

8 seconds bootloader mode.

Originally Posted By: Eogund

I have one more question: How does the buttons matrix work ? Is it similar to Leo Bodnar's BU0836?

Yes.
Leo Bodnar's BU0836:

Mjoy original: