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Joy node exhibits discrete jumps to maximum on trigger axis.

asked 2019-07-10 00:25:23 -0500

PG_GrantDare gravatar image

updated 2019-07-10 01:09:02 -0500

Hi everyone,

I am using the joy node with a clone xbox360 controller. I am experiencing discrete jumps in the sensor_msgs/Joy msg output in that when slowly actuating the triggers, the output jumps to some large value and then back to a smaller value. The axis for the triggers are represented as 1 being released and -1 being completely depressed. I am experiencing something similar to (please excuse that it is not an actual terminal message, I do not have the terminal data on me right now):


Where as you can see I am pressing to 0.25 of the total length however, it does not exhibit this. This causes, intermittently, the robot to jump in movement which causes problems since a fully depressed trigger corresponds to 60rpm. The jump is actually a very large movement.

Has anyone else experienced this issue with joy or have any ideas how to rectify the issue? Is it an issue in joy itself or might it be on my end?

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answered 2019-07-10 01:53:23 -0500

ahendrix gravatar image

You can view the raw joystick output with the jstest program. I would compare that with the output from the joy node, to determine whether the issue is with the joy node, or somewhere deeper.

If jstest does not show similar behavior, you have enough information to put together a detailed bug (and maybe even fix it, if you're feeling adventurous).

If jstest shows similar behavior, the issue could be the linux driver, some built-in functionality of the joystick, or a hardware issue with your joystick. If you have or can borrow a spare joystick, you can compare the two to see if they both exhibit the same behavior.

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Hi @ahendrix, I performed the test you recommended and founf that the problem was present in jstest too. I was able to source a genuine controller after this and was not able to replicate the issue in 100 consecutive tests. Thank you for your support.

PG_GrantDare gravatar image PG_GrantDare  ( 2019-07-17 19:18:38 -0500 )edit

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Asked: 2019-07-10 00:25:23 -0500

Seen: 210 times

Last updated: Jul 10 '19