I got it working again.
I used the schematic of the STM32F104R chip to figure out the pins for my ST-Link and flashed a standard BIN file using the STM Cube Programmer. Then I was able to flash the existing keyboard.ino.bin, and in the uConsole I had to repeat the flashing process with the flash.sh and then it worked again.
Strangely enough, clicking with the trackball now also works.
But it’s not a real mouse click because I can’t click anything with it on the desktop, but I can click in Midnightcommander.
And the volume button now also works with shift + and without -.
I didn’t really want anything more.
If it had at least said somewhere that the latest version for the keyboard was already included in the ready-made TGZ file, everything would have been easier.
Addendum:
Now it is necessary to install the Flash.sh script in /etc/rc.local, otherwise the keyboard will not work.
After switching off the device and switching it on again at some point, the keyboard no longer works. Only when I flash it again does it work again.
Similar problem when I connect something to the external USB port, whether USB stick, SSD, or other devices, then the keyboard no longer works.
Addendum 2:
It appears that the “wrong” bin file mentioned in my previous answer (uConsole/Bin/uconsole.kbd.0.4_48mhz.bin at master · clockworkpi/uConsole · GitHub) is not the wrong one , it’s just not intended for the Upload method present in the tgz file.
These appear to be images of the entire flash memory of the STM32F103R… Because after a lot of trying, I just tried the bin file that I originally used to destroy everything.
Since this appears to be an image, everything now works perfectly again.
A few tips would have been nice as to which files are for what.
I’m sure not everyone has the tools and resources to repair THAT without soldering anything.