how does the compass in the apm 2.5 suppose to work ?

[optiplex]

Hey guys and girl :)

yesterday after lots of issues i erased eeprom and downgrade upgrade fw, at the moment i have 3 rc2 and the gyros work good, the quad is stable and alt hold good
but ofcorse after eeprom erase the compass declination and settings and whatever are erased also

so i understand if i use auto declination, it suppose to gather data over few flights with gps is that right ? still didnt do those flights

what happens now, is when i connect with mission planner i see same degree all the time, i yaw the quad the number changhes but always return to same number that was 230

i did manual calibration (the stupid dance) so it changed the offset and now it always return to 83

what does it supposed to show ? the heading the quad is facing and stay there, right ?

[firey1]

yes it should stay at the oreintaion the quad is in to the compass heading it shouldnt drift back to another heading

I have had a few flights with compass in auto and in manual and notice no difference so not sure which is best opti

[optiplex]

yes it should stay at the oreintaion the quad is in to the compass heading it shouldnt drift back to another heading

thx firey

i tried the stupid dance, and entered manual declination, still returns to same heading
so i will try few flights with auto dec, hope it helps

[rickp]

Personally, this is what I do on the 3.0-rc code:

Turn off auto-declination and auto-learn
Do the compass dance, using randy';s method (face each axis north and spin)
Setup battery/current monitor and then do compassmot. Be careful doing this!

That seems to be pretty good for me on both hexa and reptile - (though I have an air-frame yaw issue on the hexacopter I think).

I have also manually tuned declination on the hexacopter - setting TUNE to 38 and range from 0 to 1000 (if doing it by mavlink direct, which is what I do - maybe range 0 to 1.0 in planner, not sure). I didn';t bother on the reptile as that hasn';t needed it.

I';m afraid I don';t use mission planner much, so I';ve no idea what my compass is actually pointing to - can';t help you there.