Rover goes the wrong way when auto is enabled

I am attempting to build a rover prior to moving on to a quad build and I’m unable to get it to correctly navigate to waypoints. I followed all of the instructions on the wiki to set things up and have no problems controlling via RC/manual. I initially had trouble with compass heading but after numerous attempts to calibrate that appears to be fixed. I don’t have telemetry but now while sitting in the driveway connected via USB the red line (current heading) looks like it is pointing correctly as I turn the truck. I can add a waypoint in flight planning and upload for the end of the driveway (~25m) then set to Auto and turn the truck until orange and red lines are aligned and the truck appears to be pointed nearly perfect for where the waypoint should be at. As soon as I arm the truck and set it to auto mode it takes off and turns almost about 160 degrees like that is where it should be going. I can drive 1/2 way to the waypoint with manual, flip on auto and it turns around and goes the opposite direction. Just to verify I was not somehow in RTL I set both home and WP1 to be near the end of the driveway and the truck still goes the wrong direction.

When sitting still the GPS locks on 8+ satellites but drifts significantly although I am right at the garage door. As I test I drove the edge of the driveway in learn mode logging waypoints every couple of seconds and it looks to be very accurate location wise when reconnecting to MP.

Any ideas what could be causing this? Where can I start to look?

MP 1.2.96
ArduRover 2.45
Pixhawk mounted ~4" above ESC
uBlox GPS w/Compass mounted ~4" above Pixhawk on nylon bolts
Spektrum Satellite
ExceedRC MadTorque crawler frame (front and rear brushed motor on axle)
ESC is ~6" below compass

Attached is a picture of my setup.


In the MP Radio Calibration page, try checking the aileron (steering) “reverse” box and see if that helps.
TCIII ArduRover2 Developer

That seems to have fixed the problem, but why? I don’t recall setting anything in the wiki about that and it never crossed my mind to try that as steering in manual worked fine, and even if the string was backwards wouldn’t that just make it take the long turn around instead of going the wrong direction completely? When I move to a quad am I going to need to do the same?

Thanks for the help.

Because it matters which side of the servo you put the horn how can the AP know how you did that? Simple fix as you have found though.

Do we reverse the “roll” mode if the wheels are rolling in opposite direction?