Interesting to hear how it's supposed to be and how it actually works for people.
Thanks MiSKLaCH for sharing your experience!
I'm doing my calibration slightly different on my standard Ubuntu 16.04. That's what I did:- Install (if not present yet) the "joystick" package. It provides commands like "jscal", "jstest", etc.
- Connect radio (in my case: start Taranis and then connect the USB port on the back to you computer)
- Calibrate radio within Ubuntu by running "jscal -c /path/to/joystick" (in my case the Taranis was mounted as /dev/input/js0 device, so I used: "jscal -c /dev/input/js0")
Follow the instructions on the screen. After a precision test, you will need to move all your analog joysticks to the min/center/max positions accordingly one after the other. - Once the calibration is done, you can check it using "jstest /path/to/joystick". This will output all actual joystick values that are transmitted to the operating system. For my Taranis I have 8 analog axis and 24 buttons. 4 of the analog axis correspond to my joysticks (channels 1 to 4) and I can verify that all analog values range from roughly -32000 to +32000 (the range of a signed short value) when I move my sticks. Furthermore I can verify that there is no dead zone around the center of my joysticks.
In my case running "jscal -c /dev/input/js0" resulted in the calibration I was looking for. - If you are fine with the calibration in your operating system, get the joystick calibration via "jscal -p /path/to/joystick". You should get a line similar to:
"jscal -s 8,1,0,0,0,4227201,4227201,1,0,0,0,4227201,4227201,1,0,0,0,4227201,4227201,1,0,0,0,4227201,4227201,1,0,0,0,-2147483648,-2147483648,1,0,0,0,-2147483648,-2147483648,1,0,0,0,-2147483648,-2147483648,1,0,0,0,-2147483648,-2147483648 /dev/input/js0"
This line is used to restore your specific joystick calibration after you disconnected and connected it again. - Create a script which restores your joystick-calibration and afterwards runs FPVFreerider
- If you centered all your joysticks before and during startup of FPVFreerider everything should be fine. However, my throttle stick is usually not centered during startup and thus I need to run the calibration in FPVFreerider every time. I can not confirm that it reuses the settings of the previous run, since I get different results when starting with different initial stick positions, while jstest returns always the same value range regardless of my initial stick positions.
Some helping references I used:
- OpenTX GitHub-Wiki: https://github.com/opentx/opentx/wiki/OpenTX-USB-J...
- A blog entry about jscal: https://blog.gimx.fr/joystick-calibration-in-gnuli...
At my current point of view, I would simply like to turn off the internal calibration in FPVFreerider and see how it works. However, this is probably not the best solution for most other people, resprectively needs some further testing and evaluation before releasing. I'm currently discussing with the author on how to evaluate this option. Furthermore, I'll take a closer look at the configuration file stored by FPVFreerider and see if I can figure out something. Maybe I'll find some time over the weekend for further analysis.
Until then, all the best,
Stefan