M4 Ladybrid Position Hold and PH controller Questions

[sandmen]

[OlliW]

[kinderkram]

I have much better results even in windy conditions - with a dipole.
Of course an active antenna will give you a faster fix and a better overall reception.
But it can do better than this.

So ... how are your mag & acc magnitudes?

Your GPS values look good btw. though you were starting between 2 houses.

The rising/sinking is usually a result of
- bad calibration
- wrong throttle factor and/or deadband
- no or wrong foam on the pressure sensor
Some use the correct foam but too thick, compressing the foam will not let it breathe.

[sandmen]

[chschmid]

[OlliW]

[sandmen]

I mean, why ever, some times it can happen, that we get a MAG reading that is off. I saw this 2 times, and on both times the default MAG dec. and incl. was set. After setting the dec. and inc. I can't creat the problem again.
Maybe this "TB" was with totally wrong mag dec. and inc.

Yes blinking is nice , but in the end, what dos it help, when I know that the GPS is not so exactly?
But good idea, and maybe we can adjust this.

So, what about GPS? What did you mean about it?

For future questions, it's always good to have the current parameter. Otherwise we need a good "Glaskugel"

[OlliW]

the dec and inc are read off from the web page given in the docu for my current place, converted to decimal using the QGC Imu calculater, and inc reversed, when calib was done, I did it 3 times and compared and double checked
honestly, the outlined reasoning appears a bit speculative on this point

blinking, let me ask the other way around: what is a blue solid led worth if it doesn't mean anything in practical terms? It's good at night though, I like that part. Just my 2 cents, nothing else.

GPS, I just have the M4 so GPS in general and GPS special on AQ is currently tautologous to me

Glaskugel, not sure for what it would currently be needed
it's a simple as that: either one has to get all the calibrations perfect to 0.000001% in order for the system to accomplish or there is a certain level of error acceptance in the system ... for both cases one doesn't need a Glasskugel ... as long as one obviously can't specify in words what accuracy is to be achieved any value is meaningless

I think I follow kinderkrams suggestion with the foam, it seems to be the best guess currently (if GPS-PH uses it), I just build a new beautifull light and wind expelling foam housing for the baro, must be quite cozy for it now

thanks as usual for all the help and patience with me, much appreciated

[Max]

[OlliW]

I think we have a bit of a mismatch in communication, and it's of course my fault, but it's my way of thinking and doing (and it more often than not works out LOL).

I'm trying to get a feeling for what is to be expected and what is needed, and how things interact. I have questions. I'm not actually asking here to spot a fault, I believe I can do that myself better, by definition, since I have the system sitting here in front of me. I'm looking for the criteria which let me decide.

E.g. you're saying that "w/out live telemetry data or a log file, you're pretty much trying to use a crystal ball to determine what is really going on", but what I'm trying is to figure out if there is actually anything going on! I'm sure you will agree that it's pointless to shoot at birds with canons when there isn't any bird. I'd like to avoid hunting ghosts. So, I find it important to first figure out if there is anything going on at all. The statements so far are interesting in that they only slowly converge.
(I assume it has converged to "it could be better", but you see the point? I still have to rely on assumptions)

I could repeat with further examples.

BTW: I assume - and I might be deadly wrong here - that with the M4 you're hoping to attract a wider audience. Iff that's correct then I think you might look at this endevaor here also from another perspective. Consider someone has a similar problem, and scans the web for help, and comes across this or any other thread, and finds many telemetry data and at the end a conclusion it's this or that, or she/he finds statements like "You should aim at this target for this and that reason", what would you think would help this someone more to get along without having to bother anyone else? The Hacc and Vacc figures in the above were usefull, the acc and mag magnitudes are useful. It would be useful to know how accurate the mag angle really has to be. Knowing that in altitude hold both the GPS and barometer data are used is more helpful than a comment that the foam is important. You have a really great docu, yet - quite naturally for such a complex project - it still has some unclear points and some info is missing. I think you want to have the above info in the wiki.



AUW is 43.40g
I've just rebuild the foam thing and first need to test it
acc mag is 9.79 on average, with the new foam mag seems to be consistently lower (ca. 1.9), another reason I first like to double-check the foam thingy
dec & inc are 1.80 an -63.87
IMU_MAG_ALGN_XY 0.0103164399043
IMU_MAG_ALGN_XZ 1.24698099171e-05
IMU_MAG_ALGN_YZ -0.0652721524239
IMU_MAG_BIAS_X -3.4659640789
IMU_MAG_BIAS_Y 3.0814640522
IMU_MAG_BIAS_Z -1.5292160511
IMU_MAG_SCAL_X 0.847387611866
IMU_MAG_SCAL_Y 0.857254385948
IMU_MAG_SCAL_Z 0.819298088551
Hacc/Vacc you have seen in the video
for the next test I have increase thro deadband to 150, to finally rule the center stick thing out
except of the foam thingy there are just the motor wires ca. 5mm above the mag, very much as in the ref build
(I however would have thought that AQ reads the mag before it powers the motors, and the mag calibration is suppossed to account for hard fields...)
what "MAG X/Y/Z plots" are you talking about??
now I've answered these questions ... just kidding LOL