I wanted to start a conversation around the roll and pitch of Arducopter drifting as you fly.


The reason is I just assembled new hardware and problems that weren't there before have now shown up in a bad way. Flying indoors in a 5ft space I was able to get up to 30° error in roll and around 10-15° in pitch. I was able to control it and it flew perfectly level the whole time, I just had to hold the stick into the corner of the radio. Lading and waiting corrects the issue.


What could cause this. I had been flying an older version of the IMU this whole time. This version has an analogue filter for the gyros where the new hardware has it as an option. You must solder the pads around the gyros to enable them. I was also flying with two slightly tweaked motors giving off a lot of vibration. This could affect the accels. 


My question is: If you have a problem like this, what is the vibration level on your copter, and do you have the filter pads soldered? 


And notice I didn't say "loss of control" or "it didn't fly stable". I had control, and it flew perfectly. It just lost it's reference to the ground and I had to compensate with the stick. Had it been worse than 45° I would have lost control. 

There are three pairs of pads, each with a white outline. (look for GYRO-XY near the relay).

Jani Solders his to enable the filter. I have never flown this board until now. I will solder them to test the filters this week.


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Hi all,


any more updates on the effect of the jumpers soldered???



I soldered my pads last night and flew a couple of flights.  It seems a little bit better but not 100% corrected, again I lift off in a perfect stable hover and steadily need more and more stick deflection to hold a hover.

It does seem less sensitive to sudden maneuvering, though, and the loiter works better, so I would say it's worth a shot.

Found the explenation of ch7 ;-)


Reply by jasonshort on June 1, 2011 at 12:08pm

I actually have that capability in the code. It's commented out right now but easy to enable. The idea is that you fly in a windless environment, a large indoor space, then hold Channel 7 high and fly it until it's perfectly level. Accels are trimmed in flight based on stick input. It works great but people were flying with ch 7 high all the time causing issues.

uncomment this line in control_modes.pde :



Ugggghhh!  I hate soldering!  In an attempt to solder the jumpers one of those little thingies next to the jumper came off!  After 30 minutes, I finally found it again.  Instead of totally destroying the board, Chris, can I send this to someone to resolder for me?  I have neither the skill, the patience nor the eyesight in working with something this tiny!

I took my quad from near my home out to the FAR site in the Mojave desert.

I tried to fly it and as soon as I took off it tiped about 30 degrees to one side and full control input

was insufficient to level it out.  The controls made changes, but full control deflection was insufficent.

It flew directly toward the larges chunk of concrete within 50 ftt and crashed on it.

I'm  now impatiently awaiting  parts from jdrones so I can fly it again.


This makes me ask the question could  these instability issues could be environmental?

This was very early in the morning so the temp was not that different, but the altitude, and humidity were very different.



Lee, do you know anyone who can solder? It seems silly to send the board across the country to me and wait weeks to get it back (I'm travelling) when there are no doubt folks you know who are handy with this stuff.
Pbreed: not that I know of, but I suppose it's possible. Every now and then the startup calibration will just get funky data from the sensors, which you'll be able to tell immediately on liftoff. (I always take off gently and just hover a few inches off the ground before doing anything else.). In that situation, just resetting the board with the quad on level ground invariably leads to a better calibration and in my experience always solves the prob.

the calibration is still some sort of pain.

if i move the quad inaccidently then i press the reset button again.

the code snippet presented by dros caspi has only be partially implemented.

if the quad moves, then the calibration has to be restarted ...

i have a spare oilpan which i need now ... i does not pass the calibration process.

i assume that the production tolerances are also an aspect to be looked at ...


the experience of soldering the pads on the oilpan resulted in a more stable flight.

when the quad is instable right after the start, then pls. re-level the quad using cli.

do it twice and compare the results.

Unfortunately I don't know anyone who is even remotely into any thing like this. I hate soldering so
much, I'd even be willing to personally fly there and deliver it. Sorry, frustrating night!
Well, I'll be back in July, so if you don't mind waiting you can send it to me. You can PM me for an address.
Please contact the store to return the defective IMU board.

I'm not sure what code snippet you're referring to. Has it been filed as an issue? The dev team is only looking at the issues queue. A link would be great.

Two things that are new in 2.0.24 that I have found really useful (1 day of testing to go before I release it):

If you hold the yaw to arm or disarm the quad, you can keep holding that to get the in-field level or the auto-trim mode.

Hold to disarm for > 10 seconds = level the quad – the LEDs will cycle quickly and stop.

Hold to arm for > 20 seconds = Auto-trim mode for only 45 or so seconds – just fly in a no-wind situation and you can trim your quad by flying it perfectly still at about 3-4 feet. The will work in any mode, but for obvious reasons, use stable or simple.


Both modes exit automatically and the LED will flash in a pattern when in each mode.



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