• Developer

    You are using the wrong input channel. You must use channel 1 input to get the failsafe managed by the PPM encoder AVR.

    Channel 5 is a direct PPM input to the main AVR, it is not connected at factory. i suppose you did some soldering behind the APM 2.5 board to get that working.

    If you use channel 1 you don't need any APM modification. Just add a jumper.

    Check it in the Wiki :

    From the PPM encoder manual :

        PPM passtrough mode

    If your receiver has a PPM sum signal output, it is now possible to pass on the PPM signal from servo channel 1 to the PPM pin (APM atmega1280/2560 PPM decoder).
    To enable PPM passtrough, short the servo input channel 2 & 3 signal pins together using a jumper strap and use the channel 1 signal pin as PPM input.
    Please note that the PPM sum signal must be standard 8 channel PPM to work with the APM PPM decoder.

    In this mode on the APM 1.4, the blue LED will blink like this  : Long - Short - short


  • Developer

    Are you connected using a single PPM wire ? Where did you connect it ?

    If you are using channel 1 APM input and PPM encoder passthrough mode, you should have a failsafe when disconnecting the RX or when no more signal enter channel 1.

    The failsafe values are 900 for throttle, 1555 for channel 5 (flight mode), and 1500 for other channels.

    This failsafe will trig only if the signal is fully missing. You should program a failsafe in your receiver as well for more safety.

    Some receivers do have 2 modes for PPM sum output : direct mode, where the PPM sum signal is forwarded without modifications, and computer mode, where you can set individual channel failsafes.

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Shivchand Jaysaval liked Shivchand Jaysaval's profile
Aug 25