Issues with ground steering

I have a rover built from a hoveround power chair. Sabertooth 2x32a motor controller, matek 405 std, bn 880 gps/mag. I have the tx calibrated, and channels assigned correctly. Pwm limits appear to be set correctly. Using the standard throttle/ground steering setup. My issue is that the ground steering parameter in the servo config screen shows that at stick neutral is 1696, min is 1500 and max at 1900 when I move the stick. I can’t imagine this is correct. Can someone please help me out.

Adjust the transmitter to get 1000/1500/2000 moreless.

They are. If I change from ground steering to RCIN1 it works fine. But I’m assuming that won’t work for autonomous operation.

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I had problems with all this and Randy solved them time ago.


Best thing is to test inputs (from the transmitter) and outputs (to the servos and/or motors) separately.

For Inputs, it’s best to use the Mission Planner’s RC calibration page (wiki). Some things to check:

  • if you see any “reversed” check boxes on this screen that are checked, please uncheck them.
  • when the sticks are centered the green bars should be around 1500 for roll, pitch, throttle and yaw channels (channels 1,2,3,4 respectively).
  • the green bars should move with the physical sticks with the exception of pitch stick which should move in the opposite direction from the physical sticks. If they move in the wrong direction, it’s best to change the direction in the transmitter (if possible).
  • do an RC calibration and hopefully:
    • the MIN for most channels will be between 1000 and 1100
    • the TRIM for most channels will be between 1450 and 1550
    • the MAX for most channels will be between 1900 and 2000

For outputs it’s best to:

  • use the MP’s Hardware Config >> Mandatory Hardware >> Servo Output page to configure the outputs to the servos and motors as described on this wiki page.
  • use MP’s Hardware Config >> Optional Hardware >> Motor Test page to test the steering and motors are moving correctly as described on the wiki here.

If you get stuck on any of the steps above just post here and we can walk you through it. Thanks for using AP!

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