New to Ardupilot, no RC plane/car experience. I’m trying to build a basic rover using a Pixhawk clone on an RC car base. I’m using the basic Mission Planner in Windows 11. I followed the Rover instructions on the Wiki very carefully, but still have this problem:
Every time I power the system, it reports “Unhealthy AHRS” when I try to arm it. If I do an accelerometer cal, that seems to resolve the problem temporarily, but it comes back when I power cycle (yes, I’m writing params after each cal).
Even when it’s not alerting with “Unhealthy AHRS”, it gives an EKF error. I’ve replaced the combo GPS/compass that came in the kit with the Pixhawk- now has a UM982 and I’m getting RTK fix and correct orientation, but still having this problem.
I’ve tried looking at the monitoring data (unit stationary with RTK lock) and I see noise on the accellerometer values that looks very small, but I don’t know what’s “normal”. If I click the red “EKF”, I get a filter display that’s basically blank- no energy.
I’ve updated from Rover 4.5 to Rover 4.6- no change. I can force-arm and drive it around with the radio control, but it keeps showing an EKF error and is in “Failsafe” mode, so I can’t switch to “auto” to navigate to any waypoints.
I’ve tried with combining the internal magnetic compass & GPS, using GPS primary with compass fall-back, or just disabling the magnetic compass.
Is there something else I should disable, or some other setting to change? Or should I try some kind of external accelerometer?
tell us about your rover. Are you using moving base for yaw? This problem can originate from wrong GPS offsets. GPS1_POS_X,Y and Z. Verify those are correct.
Yes, moving base yaw. Configured the spacing between the antennas in Uprecise and also set GPS1_POS_X/Y to the location of the “Master” antenna. I did not set Z. The orientation of the rover is shown correctly on the MP display once it has RTK lock, so I don’t think I could have the antennas reversed.
I also had the same AHRS error when I used the NEO-M8N gps/compass integrated unit that came in the Pixhawk kit.
You can save the parameters to a text file (from that same screen) and attach that instead of the giant screenshots that I removed in favor of readability.
Trying to upload a log it gets rejected as “too big” even when I choose one that’s only 2 MB. They are also all only from armed to disarmed, so I will try recording a new one tomorrow with LOG_DISARMED set to 1. Where do people generally post larger files to share?
