From what I understood of reading the wiki, manual level needs to be done before first flight, but the APM will not try to re-level on boot thereafter (unless you perform another manual level through mission planner)
At home, on a level surface I perform my manual level. However, everytime I am at the field it seems like the APM does it’s own level on boot, forcing things out of wack completely… I then have to, by eye hold the plane level and peform a manual level before flight. It’s incredibly inconvinient, and I never have the same feel because my ‘level’ is changing everytime I fly.
How can I stop this behavior? I want to set this one time and one time only. There used to be a MANUAL_LEVEL paramater which no longer exists. I’m at a loss, would appreciate any help!
Hi Raph,
Current versions don’t do level on boot, but they do calibrate the gyro on boot by default.
If you want to disable that then set SKIP_GYRO_CAL=1. I normally disable gyro cal on my planes.
Cheers, Tridge
a few questions, if you feel like getting to them… :
-any adverse effects I should look out for with SKIP_GYRO_CAL disabled?
-should I manually perform a gyro calibration periodically?
-any adverse flight characteristics I can look for that should tell me to perform a gyro cal?
[quote=“tridge”]Hi Raph,
Current versions don’t do level on boot, but they do calibrate the gyro on boot by default.
If you want to disable that then set SKIP_GYRO_CAL=1. I normally disable gyro cal on my planes.
Cheers, Tridge[/quote]
Yes Tridge, please give us a bit more insight of why you disable the Gyro Calibration and what ramifications that may have.
I set SKIP_GYRO_CAL=1 because I don’t like having to keep my plane still when booting. The only disadvantage would be if the gyro changed its zero point significantly. Small changes are fine, as the DCM gyro drift correctly quickly finds the right offset and fixes any gyro error.
I’ve been running with SKIP_GYRO_CAL=1 on all my planes since I added the option in July last year, and haven’t had any issues with it. I may change the default to to have gyro calibration skipped in a future release. I thought about changing it for the 3.0 release, but decided against it as I didn’t have time to examine enough log files to know if many users have significant gyro drift levels.
The old APM1 gyros tended to drift a lot more than the MPU6000 on the APM2.
Cheers, Tridge
Just to confirm. The plane does not need to be level on boot, but it does need to be stationary unless SKIP_GYRO_CAL =1.
If the plane is moved too much during the gyro calibration what will be the effect? Is there a warning? Will the HUD not be level?
I never remember to keep the plane perfectly still during boot and I haven’t seen a problem, at least not that I recognized.
[quote=“iskess”]Just to confirm. The plane does not need to be level on boot, but it does need to be stationary unless SKIP_GYRO_CAL =1.
[/quote]
That’s right
The HUD may not be level. In most cases the gyro calibration will cope with some movement, but it very much depends on the timing of that movement. If it does move too much then DCM will try to learn and remove the error after startup. It can go wrong though, so it is safer to either not move when booting, or to set SKIP_GYRO_CAL=1.
Cheers, Tridge