APM2.5 External Compass and Mission Planner Bug?

Today I attempted to test AUTO Flight mode and immediately noticed that my quadcopter seemed to want to fly the mission incorrectly.  My first thought was that my APM2.5 compass is not set correctly - it is turned around 180 degrees so I have it set as YAW180.  The Initial Setup for Compass does not seem to show the orientation preset value of Manual, Rotation_Yaw_180 when first connected.  I also noticed in Mission Planner>>config/tuning>>COMPASS_ORIENT is set to 4 (Rotation_Yaw_180) but COMPASS_EXTERNAL is set to 0 (internal) whereas it should be 1 (external).

The questions I have are:

1.  Is there a way to save initial setup settings in Mission Planner>>Initial Setup>>Mandatory Hardware>>Compass?

2.  Should COMPASS_EXTERNAL be set to 1 in Mission Planner>>config/tuning>>COMPASS_EXTERNAL?  If yes then there might be a bug in Mission Planner.

3.  Is Rotation_Yaw_180 the correct setting if the compass components are up and the connection in the rear?



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  • Randy,

    I use the latest quadcopter custom code and the lastest mission planner. When I connect to the APM I can't tell if the code knows I have an external compass and what the orientation is set because the radio button isn't set. When I click the radio button I am not sure it is being saved.

    Does Auto use the compass at all? I would think it would just use long/lat. All I know is that my first waypoint was north east and when I went into auto mode the quad went south east. When I looked at parameters I saw yaw180 but no compass_external was zero.

    Might you answer my three questions so I can better understand functionality, compass, and auto mode?

    Thanks for all you developers do.
  • I don't understand the internal/external parameter reference, does this apply if you are using an external compass/GPS like APM 2.6?

  • Developer

    ..but COMPASS_EXTERNAL is only in master, it's not in AC3.0.1 (the official release).

  • Michael,

    I am unclear with your response. I am using the latest mission planner and quadcopter code and had a problem with auto flight mode. When did you fix this? Is this the answer to question 2?
  • Developer

    Hi William.

    I have fixed this bug. Compass_external is a new parameter, so have now implemented this.

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