Just got into this about 2 weeks ago, and really enjoyed it.
It is so much fun! :)
But today I experienced this pitch down and dive hard unexpected movements that my plane made.
I took off 3 more times, everything seamed ok, in the begining, but suddenly it happened again, and again. Luckily i did not crash.
Then it was time to check the logs. And i saw this. 6000m???!!!
Have you experienced such a thing?
At this point, i can not trust my APM anymore.
And it does feel bad. :(
Well..actually in a number of places in the code we check is the lat is zero..and this is our way of checking if we have a good GPS value. I don't think it's likely that you'd crash but you might have trouble setting a way point at exactly lattitude zero. Now, if you live near zero lattitude please give it a try and report back! :-)
Ahhhh thank you Randy,
A was afraid that my APM might be broken. I was hopeing, that it is some kind of software issue. :)
Thank you for your attention.
Randy, could it be possible to change the APM code so that the barometer would be calibrated last in the sequence, for example 45-60 seconds after power up. This way the GPS would have enough time to get satellites and steady position for the initial altimeter calibration?
Or maybe after a reasonable VDOP value is achieved..
I'd guess that's do-able. What we do on the arducopter side is we redo the barometer calibration when you arm the motors..which is something you normally do just before take-off (and usually something like 30 seconds after power-up). I guess it's worth having a chat with Doug or Tridge who know a lot more about this kind of thing. I'll point them towards this chat.
Fortunately it was too windy to test the new code this weekend :-)
Think the fix will be out before the weekend ?
I would guess that once Chris knows, he'll be keen to push the fix but I can't make any guarantees as it's really up to Tridge, Doug and Chris. I've sent them an email and I expect it won't be too long. It'll probably need someone to do a test flight with the latest code though.
Sorry to be a pest, but can I tell the APM to only, or at least mostly use GPS data for altitude ?
Is this a new bug, if so, what version of the ArduPlane code would not have it ?
Here in Africa it is not uncommon to have daytime shade temps deep in the 30's
Must admit, I haven't seen this bug in any previous flights, using older code, will check later if I still have a copy.
You can choose how much APM uses baro vs gps (ALT_MIX)
Thanks, that would be great :)
Randy , could you please comment on how this is possible ?
bad GPS fix, gives me realistic,changing altitude with a huge offset.
I'm having the same issue. Before GPS lock, the altitude fluctuates around zero as expected. When the system gets GPS lock, it seems to be a random number between 60 and 500 that is a constant offset in altitude that persists as long as the system is powered. When you restart the ardupilot the number changes, but it is never near correct.
Using a MediaTek GPS with most recent Arduplane on APM 2.5.
Any thoughts on what could cause this?