I'm trying to calibrate my compass offsets using xbees for the communication. Everytime I get the menu in the CLI it cuts off around line r


r - Reset to fa


And when I use c to do compass offsets it streams the numbers for about 15-30 seconds and then stops and the IMU instead of walking red orange green it stays solid green?


Does this mean the IMU has crashed? I can only restart it to get it back and also have to debrick the xbee also because it seems to get corrupted in the process.

Views: 501

Reply to This

Replies to This Discussion

I think you likely need to increase the baud rate of the xbee.  The CLI menu is displayed all at once so it's a reasonably large amount of text that needs to get through the Xbee in a short period of time.  I think what's happening here is that the outboard buffer on the APM is filling up.  Sorry, I'm not sure if the APM crashes when the buffer overflows (I hope not)


Personally I've never used the XBee to do configuration although i believe many others have.

I always set the xbees to 115k. Is that the right rate?


When the IMU is in CLI mode (walking leds) and it stops and displays solid green, does that indicate it's crashed?


Also when I pull the battery and restart, (before connecting the blue xbee wire, to avoid bricking it) the blue and red lights flicker until I plug in the blue wire and then the red and blue stay on and I have to debrick it.


The reason I was wanting to do the magneto configuration wirelessly is so I can spin it around without risking pulling out the usb cable. Most people are doing it via usb?

I received at the end of March a HMC5843 - Triple Axis Magnetometer Rev 1.2


Do you know if this has the noise issue resolved? The last one i had to remove the little resistor but this time I soldered it to the IMU and forgot to check first. :-/


Is 1.2 ok? It's the latest version?


   The noise issues were resolved within days of that post from Jordi going up saying they'd found a problem.  That was months ago and I haven't heard any compliant so I think it's all a-ok.  I've personally ordered two mags since that time and they're working beautifully.

The one I modified (after I took off the resistor) worked great and locked in very tight. This new one every 5 or 10 seconds does something like a 10° turn left or right but always returns to the correct position. Maybe it's related to PID values I have for YAW control? I'm just using the default values and not even sure where to change them but I guess they are changeable?
The quad does a 10 degree turn or the magnetometer output does (and the quad tries to compensate)?

Hi Bones :)


The mag output does the turn. I'm not touching the left stick. I can be flying in perfectly calm space and it will twitch to the right and then go back. If I fly circles without touching the yaw stick, it will stay straight so it always recorrects itself.


One thing that I'm not sure about is on my transmitter (JR9503) I can't leave the trim centered on the yaw. If I center it then it slowly turns in that directly just like if I was not using the magnetometer. That part makes sense since it's trimmed in that direction but why does it NEED to be trimmed off center? Does that mean I need to redo my accelerometer offsets? I used CLI on a level surface when I did it and when I turn on the copter, I try to keep it as still as possible because I understand that can cause some error in leveling if you turn on the quad so that it initializes with the copter not stable.

your transmitter does NOT send a clear 1500 signal when centered (more like 1540), so you need to trim it a bit to make it a 1500 signal (which actually IS center for ardupilot)
do i see if it's transmitting 1500 by using the configurator app or is there some other way?
Use the ArduCopter Configurator and select Transmitter Adjustment from drop down menu.  You can adjust your trims.
I did that now but do I center all my trims first? If I do that then I never get a 1500 value as the center. Also when I complete this calibration in configurator, where does it save these stick values? I thought you only needed to use CLI or is configurator still needed for this transmitter adjustment?
Dammit, Jim, i'm a doctor, not a debugger!

Actually, i'm an EE student, but nevermind that ;)))
Keep the quad on the ground for a while and watch your telemetry in the configurator (the artificial horizon in particular).

See if there are any sudden jumps or spikes in the heading readout.
Then redo that with the motors armed (take the props off, of course).

It might be a matter of magnetometer interference, this should rule it out.

Just out of curiosity, any big feromagnetic bodies or EMF sources in the vicinity of the spot where you fly your quad? Sometimes a passing car is enough to throw a magnetometer off...

Reply to Discussion


Season Two of the Trust Time Trial (T3) Contest 
A list of all T3 contests is here. The current round, the Vertical Horizontal one, is here

© 2020   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service