NAME

       evdev-joystick - joystick calibration program

SYNOPSIS

       evdev-joystick --help
       evdev-joystick --listdevs
       evdev-joystick --showcal <device‐path>
       evdev-joystick  --evdev  device‐path> [--axis <axis>] [--minimum <value>] [--maximum <value>] [--deadzone
       <value>] [--fuzz <value>]

DESCRIPTION

       evdev-joystick calibrates joysticks.  Calibrating a joystick ensures the positions on  the  various  axes
       are correctly interpreted.

OPTIONS

       --h, --help
              Print out a summary of available options.

       --l, --listdevs
              List all joystick devices found.

       --s, --showcal <device‐path>
              Show the current calibration for the specified device.

       --e, --evdev <device‐path>
              Specify the joystick device to modify.

       --a, --axis <axis>
              Specify the axis to modify (by default, all axes are calibrated).

       --m, --minimum <value>
              Change the minimum for the current joystick.

       --M, --maximum <value>
              Change the maximum for the current joystick.

       --d, --deadzone <value>
              Change the deadzone for the current joystick.

       --f, --fuzz <value>
              Change the fuzz for the current joystick.

CALIBRATION

       Using the Linux input system, joysticks are expected to produce values between -32767 and 32767 for axes,
       with 0 meaning the joystick is centred.  Thus, full‐left should produce -32767 on the X axis,  full‐right
       32767 on the X axis, full‐forward -32767 on the Y axis, and so on.

       Many  joysticks  and  gamepads (especially older ones) are slightly mis‐aligned; as a result they may not
       use the full range of values (for the extremes of the axes), or more annoyingly they may not give 0  when
       centred.   Calibrating  a  joystick  provides the kernel with information on a joystick's real behaviour,
       which allows the kernel to correct various joysticks' deficiencies and produce consistent output  as  far
       as joystick‐using software is concerned.

       jstest(1)  is  useful  to  determine whether a joystick is calibrated: when run, it should produce all 0s
       when the joystick is at rest, and each axis should be able  to  produce  the  values  -32767  and  32767.
       Analog  joysticks should produce values in between 0 and the extremes, but this is not necessary; digital
       directional pads work fine with only the three values.

SEE ALSO

       ffset(1), jstest(1).

AUTHORS

       evdev-joystick was written by Stephen Anthony, based on VDrift's G25manage tool.

       This manual page was written by Stephen Kitt <steve@sk2.org>.