Calibrating embedded Linux touchscreen controllers requires querying and configuring absolute axis bounds (ABS_X, ABS_Y, ABS_MT_POSITION_X, ABS_MT_POSITION_Y).

evtest Input Axis Query Command

Terminal Commandsbash
# Inspect input event device properties and axis limits
sudo evtest /dev/input/event2
 
# Sample output:
# Absolute Axis ABS_X (0x00)
#   Value      0
#   Min        0
#   Max     4095