u/HeronOk2131

Github source is allready updated.

There is an Error in the keyboard driver for kernel 6.18.29:

picocalc_kbd.c:591:5: error: implicit declaration of function ‘del_timer’; did you mean ‘add_timer’? [-Wimplicit-function-declaration]
  591 |     del_timer(&g_kbd_timer);
      |     ^~~~~~~~~
      |     add_timer

I have to Change del_timer to timer_delete in the keyboard source code solve this issue:
picocalc_kbd/picocalc_kbd.c

//del_timer(&g_kbd_timer);
        timer_delete(&g_kbd_timer);
        g_ctx = NULL;

It is recommended to redownload the Github Repository: (remove the old download)

git clone https://github.com/ironat/picocalc_trixie

Then execute the Keyboard install steps again. You have only to execute the script again:(With ssh)

cd picocalc_trixie
chmod +x setup_keyboard.sh
sudo ./setup_keyboard.sh

BTW: You have to do this steps (Download and recompile) every time you get a new kernel.