I have double checked everything and completed auto trim and auto tune… hex flies not to bad in Stabilize and alt hold mode… but it all goes nutso when I flick the switch to loiter… hex takes off in any given direction and then tries to ram itself into the ground… so far I have managed to recover it all by flicking back to stabilize mode…
I have disabled the onboard compass and I am using a neo7 ublox with compass… , I have tried calibrating the compass with all different variations in the manual drop down box…
Have also used a multi meter to test that there is no TRACE connection with the onboard compass… but here’s the weird thing that gets me… with just the FC plugged into mission planner (no external compass/gps), and I try to calibrate the compass, then nowt happens… but when I check the FLIGHT DATA screen then the onscreen compass moves in correlation with the direction that I move the hex …so, is the onboard compass still actually functioning???, even though there is a BAD COMPASS HEALTH warning on the screen…
sorted to a point where it’s flyable in loiter mode…
as of yesterday I fitted the apm to an anti-vibration mount on the hex and then I recalibrated the compass and accel… still a bit twitchy in the air and craft wanders up/down and from side to side…but at lease it isn’t nutso on me when I flick the loiter mode switch…
I have as of this morning reflashed the FC to firmware from 3.2.1 down to 3.1.5 and will test it all soon to see if that has made any major improvement…
You have to disable the onboard compass to get it to use the external one. On older APM 2.5 boards you had to cut a jumper trace to disable it, but on most APM 2.6 and newer boards there is a header jumper that you have to remove - this maybe your problem. Until you do that it’ll continue to ignore the external one, and it’s still seeing the internal compass per your first message! Somehow it’s still connected…
The problems with firmware 3.2.1 should go away if you try changing the parameter INS_MPU6K_FILTER to 20 instead of 0. In older firmware the value of 0 used to default to 20 for APM 2.x controllers, but in 3.2.1 they seemed to have made it an absolute value. I’ve tested this myself and setting it to 20 solved the problems I had running 3.2.1 on an APM 2.x flight controller.
onboard compass was already disabled by breaking the trace, …
I am not long back in from a few test flights… have it more or less nailed down… still a wee bit twitchy in Loiter mode… but a damn sight better than what it was…
Loaded 3.1.5 Firmware, and replaced the mounting board, moved the GPS to the front of the craft, I then re-calibrated all that needed doing, and then I took it out to the field and took it off in stab mode and flicked on autotune… once autotune was done I landed the craft and saved the settings… I then took the craft back up and flicked it into “loiter” , wasn’t bad but could be better…so I then flicked it into Alt hold and flicked the auto tune switch once more… after this was done again I landed it and saved the settings…
Took off in Stab mode once again and flicked it into LOITER… yay… more or less rock solid… as I said earlier just a wee bit twitchy…
just need to sort out throttle as it climbs and drops in stab mode…
