evdev-joystick(1)           General Commands Manual          evdev-joystick(1)

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>.

evdev-joystick                  April 19, 2016               evdev-joystick(1)