We have an external compass that gives us AHRS data (as opposed to raw mag/accel/gyro data). I would like to feed this data into Ardupilot from a companion computer and have Ardupilot use the external solution over the internal AHRS solution. I tried disabling the internal IMU (parameter INS_USE=0) and just sending a mavlink attitude message directly over the serial port (I was getting a heartbeat so I know there was a serial connection), but that didn’t update the roll, pitch, or yaw. Then I tried following this topic using Lua scripts, but I couldn’t find any examples that set roll, pitch, or yaw. I did find a method on line 1710 of this document, but I can’t find any examples that use this method and I’m not very experienced at Lua so I don’t really know what “instance” is. Can someone help me out? I feel like someone would have asked this by now, but I couldn’t find any topic on it.