Delayed switching of Modes

I have experienced a delay when switching from Alt_Hold to Stabilize and this caused a little crash. The funny thing is that it 'feels' like the same type of lag when the rudder commands become unresponsive.

I have logged an issue here:

Has anyone else experienced this?

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  • Ok everyone - I have found a solution! Eureka - Olivier, without your slow -> fast blinking comment I would not have found it. I got the latest hex file from and loaded that into the AtMega328 PPM Encoder chip and voila, it can read the PPM inputs from the Fr-Sky receiver. (* the blue ppm indicator led now blinks slowly when low throttle, and faster when high throttle)

    I put the link in this post so that others might not have so much difficulty determining which is the correct hex file to load ;-)


    Now I can start flight testing again - Thanks all

  • Developer


    The Fr-Sky receiver is known to cause problems to the ppm encoder. The ppm encoder firmware has channel freezing problems as well with receivers using multiplex mode ppm frame (older 35,40, 41 and 72 Mhz receivers).


    I would recommand to use anohter receiver, or if you have an ISP programmer, you could update to the new Arducoder firmware 0.9.83 available in the ardupilot mega repository.



    I'm using this new firmware since a couple weeks and didn't see any problem. Nevertheless read carefully the readme file and test it seriously before to fly because it is not widely tested yet.



  • I think I may have found the solution to my problem -
    For all my flying I use a Hitec Eclipse 7 transmitter with a Fr-Sky 2.4GHz TX Module. When doing HILS testing I found the unpredictable Mode switching and rudder lockout. However, I then tried a Futaba T6EX with an OrangeRx receiver and the mode switching works perfectly, and I also haven't had any issues with the rudder commands.
    Could it be that the Fr-Sky receiver doesn't like working with the APM?

    Thanks Bjorn for tickling my interest into investigating the Transmitter/Receiver pair. I just can't understand why the throttle, roll and pitch would 'feel' ok on the transmitter and the other channels become 'confused'.

    Anyway, just VERY glad that we can start flight testing again.


  • My first thought is definitely: "Radio glitch". I would check my receiver setup, especially the antenna placement and do thorough range checks.
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