Quad improvements

[artis]

Hey guys. I'm having progress with my quad and I'm really happy so first thanks for helping me in my previous threads.

Now to the questions.

1. Levelling. I am flying the quad in angle mode. Which is nice but not perfect. I do have drifting even without wind. When there is wind the quad is not acting well. To be honest I thought it was normal initially until I saw a DJI Phantom 2. This thing was holding it's perfectly stable position even with wind. Is there a way to achieve this with MultiWii 2.5 SE?

2. My second question is kinda related to the previous one. In angle mode when I let go of the sticks the quad should level itself and balance. Here comes the problem my idle position of the sticks on my Turnigy 9x is not 1500 but something like 1450 or something similar (don't remember). I found a way in the meny to subtrim it up to 1500 which should be fine. But still 1 problem remains. The idle position of the sticks is not a perfect 1500. Sometimes it's 1498 or 1501. Is there a threshold in angle mode to ignore such small differences or it needs to be exactly 1500 in order to maintain perfect level?
If it needs to be 1500 is there anything I can do to setup some sort of dead zone of about +-3 ?

3. In general. Do you have any advices on how to make the copter as stable as possible. I'm interested in FPV. I am not interested in acro at all.

Thank you very much.

[Arakon]

1) The Phantom FC has GPS. Some drift is normal without GPS hold.
2) Look at the deadband option in config.h.
3) Wrong FC, basically. For "as stable as possible" you'll need GPS and a FC with current sensors (the baro on the SE is outdated). If you have the cash and don't want to fly, but rather have the FC fly for you, you'll need a Naza flight controller.

[fuh]

erm.. APM FTW.

[artis]

I don't think it's the GPS hold as the drone didn't move even a centimetre in any direction and no gps is that pricise.

Thanks for the info.

[waltr]

I have a couple of quads running MW and once properly trimmed and tuned they will hold a fixed position hands off. These do this even in ACRO mode (no self level).
There are many things that are needed:
1- A solid, rigid frame.
2- balanced motors and props for low vibrations.
3- Some gryo LPF defined.
4- Some DEADBAND helps so that sticks look centered to MW.
5- Proper PID values (this is the hardest to figure out and can take a good amount of trial).

[artis]

What do you think about this frame http://www.ebay.com/itm/Tarot-TL65B01-I ... 43cb6fcef2

Are 4xSunnySky x2212-13 going to be enough for this frame? I won't attach any heavy camera. I'm thinking about a Boscam TR1 camera with integrated transmitter.

[artis]

Finally I decided to go for a smaller rather than bigger frame so I ordered the F450.

I have played with magnetometer lately and se t deadband to 5. This fixed the stick idle position problem.

But (of course) a new problem arised...
Looks like the magnetometer wasnt doing anything so far because I didnt set the deadband.

Now with the deadband set and idle sticks properly detected the magnetometer is actually activated in idle hover and the results are.... terrible...

The quad starts to spin moderately fast on the left or the right (it picks the direction randomly every time I idle it).

I hooked the board to the PC and made a few tests with the copter tied down. The magnetometer shows significant deviation when throttle is applied (~ 15* at max throttle).
I can see this being a problem, even deviated it is pretty stable when the throttle is steady the readings do not change a bit.

I mapped the magnetometer to AUX switch on the transmitter. When the rotation starts if I switch off the magnetometer the quad stops right there, so it is 100% sure to be magnetometer problem.

So Im really puzzled - why is the quad behaving like this?

P.S. I did calibrate the magnetometer by rotating it at at least 360 degrees on all 3 axis (several times tried this).
P.P.S. I havent set declination in the config, but I can't imagine this being the problem.

[Arakon]

Your power wiring is creating a magnetic field that changes the more you throttle up. You have to move the magnetometer out of range of that field.. i.e. move the FC higher up or use an external magnetometer and put that somewhere out of the way.