help Debuging the Arducopter???

I haven’t had time to fly for a while so I’ve forgot some of the details about this problem. But I would really like to “debug” my copter today. So what I’m looking for is some advice on how to do it, and what more information I can supply here.



I’m using the MB1200 XL-MaxSonar. It was working great for a while then suddenly it stopped. I’ve tried it over multiple versions of the firmware still nothing. When I turn on the altitude hold it just stops and falls out of the sky. No clue way.



I’m also having a lot of problems with the compass, it looks like it forgets what’s north, some kind of disturbance. So no chance of loitering. I’ve tried to get help before but not yet solved it


Any one?

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • Ok now loiter is working more or less, it is a little aggressive but it holds the position. So I tested RTL, and that works to. BUT when it gets back to it's launch position it circles for 5 sec or so, then FALLS OUT OF THE SKY!!!! Tried it twice same result, any idea what this might be.

    Any help would be appreciated, now flying v2.3
  • Still getting bus errors but the performance is much better. Not getting closer to this mystery
  • I went back to v2.3 of the firmware and now suddenly alt-hold is working with baro :) Still struggling with loiter tough.
  • Just did the test, no errors while running of battery (BEC) power. AKA no luck :(
  • Just realized that the last test was done on USB power, maybe I'm on to something. I will try with battery(BEC) power tomorrow
  • Ok now i tried running the test found in the library folder, you can see the output in the shared folder.


    No erros with the logic analyzer


    Still no errors with the logic analyzer

  • Ok forget the (while motors are running), looks like I can get errors any time. But as of now it looks like they might be coming from the baro. I guess this will be a pain to replace. Any one got experience with this type of problem?? Or toughs on what might be causing this problem? Or if any one has run a logic analyzer on the I2C bus, have you been seeing errors?

    I think the only time i did not have these problems was back when I was using the ArduPirates code. (that might just have been luck)

  • Ok getting pretty sure about it being a I2C bus problem. I get errors on the bus when i test it with the motors running. Not sure what the cause is yet, but at least it's progress.
    If you want to see the output it's under the link above.
  • OK so since the baro and compass is acting up it's pretty clear that this must be something on the I2C bus (I think). So I hooked up a logical analyzer, to see what was going on. If you want to see the result visit the link under. Have not had time to really dig in to it, but at least there is no errors. You can see bought the mag and baro data in the capture.

    I also added images of the capture, for those not using OLS


    ShareRoom - SpiderOak
  • Hi again


    Finally had some time to work on my copter, and it got even more confusing.


    As you guys suggested I resoldered all the connections for the sonar, still same problem.


    I also replaced the magnetometer with a new one and resolderd the connections. But still have the same problems.


    Everything else is working great no problems at all. Checked for shorts could not find any after visual inspection

This reply was deleted.


Hiroki Tanaka liked Hiroki Tanaka's profile
Oct 13
Derrick Davies liked lisa TDrones's profile
Sep 23