APM 2.5 set up

Posted by Paul N Braida M.E on November 6, 2014 at 5:12am

I have an interesting issue with my APM 2.5's.

First of all I have a pair of them.One is set up programmed and working ppretty well.The other however is acting oddly.

I went through the same set up/program method but when connected to Mavlink and monitoring it on my computer screen the compass is approx 180 degrees out of position as compared to an actual real compass and also the axis seem to be mixed up.Roll axis shows as pitch and pitch shows as roll axis.

The accelerometers were calibrated as shown and as was the compass.During compass cal,over 6,000 points were picked up for reference.

The other issue on both is getting the external LED's to work properly.I have an external driver board for them.For example, the Led plugged into the GPS socket flashes continually even with a GPS lock.The only time is glows steady is when the  Quad is armed.The arming led seems ok and the buzzer in plug #5 works fine.

Any help with these issues is appreciated.

thanks

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Replies

  • Dean Miller November 6, 2014 at 11:40pm

    Hi Paul, I have not had a chance to try this yet but here is the info:

    If you choose to control the pins directly from the APM, you must choose LEDs which have a current draw lower than the maximum permissible current of the AVR chip on the APM: 40mA.

    For AC3.1.5, the pinout of the APM is as follows:

    • A4 : AUX led
    • A5 : Beeper – can drive a piezo buzzer directly (see below)
    • A6 : GPS – will flash with no GPS lock, solid with GPS lock
    • A7 ~ A11 : Motor LEDs

    Which LEDs are active and when they blink is somewhat configurable through the LED_MODE parameter which can be set from the Mission Planner’s CONFIG/TUNING > Standard Params > Copter LED Mode drop down.

    For AC3.2, the LED_MODE parameter is removed but all the following reduced set of pins are always active:

    • A4 : Motor LED
    • A5 : Beeper – can drive a piezo buzzer directly (see below)
    • A6 : GPS – will flash with no GPS lock, solid with GPS lock
    • A7: Arming LED

    It is on this wiki page. I got the info from Charles Lakins, also in this forum. Good luck.

    • Paul N Braida M.E > Dean Miller November 7, 2014 at 5:05am

      Thanks again Dean!

      I have all this information already.I purchased an optional led board with driver transistors on it already and it lights up great.what I found is that the GPS light will blink even with GPS lock,but will go solid only when I arm the board.A7 seems ok.A4 appears to do nothing but the beeper in A5 works perfectly.I did not see the parameters buty will go back and look.

  • Dean Miller November 6, 2014 at 7:40am

    Yup, something got messed up. Check out the AHRS_ORIENTATION in the full parameter list, its halfway down on the first screen.  I can't recall default, mine is hanging upside down so I use "8:Roll 180", I think default is "0" but check that parameter against you're board that is working properly.

    I have the same problem with my LED board, I think it got screwed up in a firmware change, it used to work fine and I haven't tried to fix it yet, hope to see a solution here.

    • Paul N Braida M.E > Dean Miller November 6, 2014 at 9:52am

      Ok thanks!

      I changed this AHRS parameter to a value of zero.The compass direction and pitch axis is fine now but my roll axis is reversed.Right is left & left is right.I tried a couple of other parameters but they screwed up the compass and pitch again.

      Any more input is greatrly appreciated.

    • Dean Miller > Paul N Braida M.E November 6, 2014 at 10:16am

      Not sure I can help much more, but is your compass internal or external?  If external there are orientation adjustments for that too, under compass setup.  If you are just looking at the HUD in mission planner the roll axis normally does look reversed, its the way artificial horizons work. Otherwise maybe your radio channel needs to be reversed for that model, that happened to me once when setting up a radio.

    • Paul N Braida M.E > Dean Miller November 6, 2014 at 10:26am

      Hey thanks Dean! you are a wealth of information.My compass is internal and yes I am looking at the HUD on the computer screen.This is where I first found my compass and pitch axis out of whack.The parameter was set to a value of two and I changed it to a value of zero.
      Ok if it is normal for roll to appear reverse in the HUD then my issues are resolved and I thank you very much.Now to solve that external LED problem.
      By the way my radio is set up proper.I've had props temporarily mounted and the motors spooled up.Any directional command from the radio works correctly.
      Thanks again

    • Dean Miller > Paul N Braida M.E November 6, 2014 at 12:54pm

      Ahhh, compliments will get you everywhere, just trying to contribute back to the community some.  Now you have me thinking about those damn LED's that I ignore because they don't work right, so I'm looking into it.  It used to be that the LED_Bitmask parameter had to be set to "11" but now that parameter appears to be gone, I'll keep you posted when I find out what happened there. 

    • Mike > Dean Miller November 6, 2014 at 5:43pm

      Someone on RCG says he got around this by downgrading to 3.1.5, setting the LED parameter, then reloading RC14. Apparently the setting is retained through the change. Means doing all the setup/calibrations again though.

    • Paul N Braida M.E > Mike November 7, 2014 at 5:17am

      Thanks Mike!

      what is the disadvantage of going to 3.1.5?

      I'm not sure of the difference between the two versions.

This reply was deleted.