I did some new tests.
I have a mini bluetooth gamepad(8bitdo zero 2), which was used on my Boox ereader as a page turner.
This gamepad has multiple working mode, one is emulating a keyboard.
I connected the gamepad with Libra 2 successfully.
When I press the button on the gamepad, The letters do appear in the input box of Libra 2.
Unfortunately, the default keyboard setting of this gamepad is not the direction keys on the keyboard, but some letters( J K I L M O N....)
Then I telnet to the Libra 2, find the /dev/input/event3 is the gamepad
running evtest /dev/input/event3 and press the button
Code:
Testing ... (interrupt to exit)
Event: time 1638439135.755665, type 4 (Misc), code 4 (ScanCode), value 70009
Event: time 1638439135.755665 ------- Report Sync ------ x: 36808 y: 36728 p: 0 ------------
Event: time 1638439135.849393, type 4 (Misc), code 4 (ScanCode), value 70009
Event: time 1638439135.849393 ------- Report Sync ------ x: 36808 y: 36728 p: 0
So here is the new question, how to intercept this scan code and map it to the normal page turn key? I apologize in advance for my poor knowledge of linux.