(Serial) Mouse Cursor moves too fast and jittery to be useful

[megatog615]

VID_20260511_211203-10mbMB.mp4

Note that I am using a USB4VC converter to convert a USB mouse to serial.

[ghaerr]

In the mouse driver drivers/mou_ser.c, you'll find these two configuration parameters:

#define SCALE       2   /* default scaling factor for acceleration */
#define THRESH      5   /* default threshhold for acceleration */

Try setting SCALE to 1 and playing with the THRESH value to see if this helps for your mouse. If not, we might have to look further into the mouse driver filters in engine/devmouse.c and possibly play with JITTER_SHIFT_BITS.

A final option would be dividing the input mouse x and y values in the mou_ser.c driver to scale the amplitude changes down. This will involve knowing whether your mouse is sending relative or absolute coordinates.