DOKK / manpages / debian 11 / joystick / evdev-joystick.1.en
evdev-joystick(1) General Commands Manual evdev-joystick(1)

evdev-joystick - joystick calibration program

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>]

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

Print out a summary of available options.
List all joystick devices found.
Show the current calibration for the specified device.
Specify the joystick device to modify.
Specify the axis to modify (by default, all axes are calibrated).
Change the minimum for the current joystick.
Change the maximum for the current joystick.
Change the deadzone for the current joystick.
Change the fuzz for the current joystick.

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.

ffset(1), jstest(1).

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

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

April 19, 2016 evdev-joystick