I posted an update to the ArduIMU. If someone else is working on this, please feel free to email me happy@happykillmore.com.
http://code.google.com/p/ardu-imu/downloads/detail?name=ArduIMU_1_8_1.zip&can=2&q=
Fixes in this post:
1) NMEA protocol now works (typos in update function and missing PMTK in init function)
2) Magnetometer works (typo in setup where it said MAGNETOMETER == 1 where it should have said USE_MAGNETOMETER == 1, AP_Compass must be changed to APM_Compass, Buffer mapping differs from AP2.7 and older code in AP_Compass.cpp)
3) Added blinking lights function to GPS parsing routine (blinks when there is no lock but valid message from GPS unit)
4) Added #define GPS_CONNECTION 0 // 0 for GPS pins, 1 for programming pins (this allows the user to select where the GPS is connected)
Please note that this isn't considered an "official" release and it may well get deleted... I didn't check with anyone before making these changes and posting this :)
Known issues with this version:
1) When selecting BINARY output, GPS light will not blink (#3 above). Simple fix: Add if (GPS.fix >= 1) to a new line 129 of output.pde
2) Removing/disconnecting GPS will not disable GPS lock light.
Comments
I can reduce this orientation matrix so you have to define it once at compile time. I'll do that this week or on the weekend. If you want to test, you could chop down the size of the rotation matrix in APM_Compass library to just a single matrix (just make sure it's the one you want!).
Thanks for updating the manual. Can you add in the blue light will go out if the GPS signal is lost for 1/2 sec. I might need to extend time for slower Hz GPS units... what is the recommended minimum and max Hz rate for AP and APM?
Chris, are there any plans for a new ArduPilot (not Mega) source code release (ie 2.8 or 3.0) that use the APM libraries. I personally would have called ArduIMU 1.8 version 2.0 because of the size of the change.
Actually the magnetometer stuff is on the arduCopter wiki as well including a little extra info on setting the orientation and declination.
http://code.google.com/p/arducopter/wiki/Quad_Magnetos
but this is only valid if you're using the latest versions of the APM_Compass library from the arduCopter SVN. The zip for the arduIMU 1.8 shipped with slightly older APM_Compass module (maybe the one from the arduPilot svn)
@happy - please PM or email me - i'm having trouble recreating the issues you're seeing with the magnetometer.