Joystick calibration under linux
I don’t know off the top of my head of a graphical joystick calibrator for linux, but there is a command line utility that’s dead easy to use…. jscal I found the tip in a flightgear mailing list after having a hard time with one of the first flights. The stick was very far off center, I had to pull almost all the way to the right to keep level. Anyway… here’s the tip.
Joysticks are calibrated at the kernel level. So, for instance, a program like flightgear looks at the device and doesn’t have a means for adjusting the data to correct for centering. It just assumes what it sees is accurate. So, here’s how to calibrate.
jscal -c /dev/js0
This will have you move the 0-axis to it’s minimum, center, maximum, then axis-1, etc. etc. etc. The only trick can be guessing which axis you need to use if you have more than 2. The other point to mention here is that if there are more axis’ detected than you have it’s ok. Just follow the instructions and if there’s no change on an axis, keep pressing a button to move through. It’s really fairly easy to use.
But what happens after a reboot? You lose the calibration… UNLESS…. you do this.
jscal -p /dev/js0 > calibrate-stick.sh
Which prints out your calibration information to a file, then after the next boot. (Maybe in a login script?)
sh calibrate-stick.sh
the above will “recalibrate” based on the settings that you’ve just assigned.
Some distros may deal with this, I suspect there may be GUI frontends for this, but it was the quickest route I had to getting to fly straight and level.