Board Orientation and AUTO Mode

Okay, so as I was trying to figure out what was wrong with my throttle, I swapped the radio system out to the stock Traxxas receiver. I use a 4 channel remote from a Summit and modified the thumb switch to 3 positions so I could use a ground radio to control the truck. I've raced these things so it's much easier for me this way. It also made for a much cleaner installation. However, it required me to change the orientation of my board to get it to work.

Now, the board is mounted 90 degrees to the right so the forward arrow is pointing to the right of the truck instead of the front. I went into the Advanced Parameters in the MP and changed the AHRS orientation to Yaw 90 and rebooted to get things set to what I need it to be. I changed to the HUD to make sure when I pitched and rolled, it reacted properly and all was well. I noticed that the yaw seemed to be off some but wasn't sure if that was due to the GPS or magnetometer. I didn't think much of it but it seemed to be off by about 90 degrees, what I set for the offset in the parameters. I tried a few things outside and couldn't get things to work so I tried messing with the settings some more to see if that would take care of the yaw. Pitch and roll values (granted they aren't used for a rover right now) followed with whatever setting I made but for whatever reason, yaw was always off. I'm stuck now and am not sure what the problem could be. Any insight?

Then deciding I wasn't going to figure that out, I decided to at least make a go at a mission. I set home, made a few points away from me, flipped the switch, and it took off...in the wrong direction. It always seemed like it was trying to go home but it was ALWAYS 180 degrees the wrong direction. I tried setting a few points further away to see if it made a difference and there was no change. Finally, I put the point opposite where I wanted it to go and it took off the way I originally wanted it to go. Basically, if my first point was supposed to send it East, then it took off going West.

Not knowing what was going on, I went inside and tried messing with the AHRS orientation settings some more and only confirmed what I found above. Yaw seemed to be off but everything else was fine. With the wheels off the ground, I would set a point, put it in AUTO, then it would try to take off going the other direction.

Bottom line, it thinks East is West and North is South. Something is obviously not right. Any ideas on this problem?

Finally, this is more likely a tuning issue but when I did let it just go, it seemed to weave a whole lot trying to get to the next point, kind of like it's completely out of tune. Seeing it has a magnetometer on it, I expected it to be smoother but maybe it's just tuning I need to do? It's only moving along at around 4 m/s at the moment. If it helps, I have the compass turned on and manually input the magnetic declination. It was around -15. Is this just a tuning issue?

Any help regarding the three points would be useful. Now that I have something somewhat working, I can help out with some more testing. I need to 3D print a few brackets to make things a little easier to work with so I can get the battery out quickly for charging but it's finally moving along after a year of putting it off for other things!

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  • How did you go about connecting the two steering servos with the other receiver? Did you use a reversing Y-harness?

  • Admin


    You can do a level calibration with the level command in the CLI. It is located in the "setup" section of the CLI.

    Since you are mounting your AMP at right angles to the line of travel, changing the AHRS orientation for the APM may only affect the INS and not the compass. You may have to mount the compass by itself facing forward on your chassis away from any magnetic fields. There are instructions in the Wiki on how to add an external compass to the APM2.5.

    Are you sure that you have the steering setup correctly in the auto mod?. I had to reverse the steering in the radio calibration for the auto mode as it was 180 deg out from the manual mode which is adjusted at the R/C transmitter.



  • T3

    Would it make more sense for at least the yaw to use the Live Calibration or should I just manually input the information?

    Also, where is the level setting or is it something that doesn't really need to be done on a rover? I assume it just happens when you turn the APM on for the first time.

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