PPM output waveform

I am working on an engineering senior project to make a UAV.  My job is to get the plane flying, while two teammembers work on the payload.  

 

The design criteria for the project required the use of a TI microcontroller somewhere in the project.  I am trying to replicate some of the functionality of the PPM encoder on an MSP430.  I already have it measuring all 8 channels out of my Flysky radio (probably quite inefficiently), and can send that data out of a serial port.  However, I have not successfully made a PPM signal that ardupilotmega can interpret.  I might have a poor conceptualization of the signal, or I might just be going about it the wrong way.  Could someone send me a picture of the whole PPM waveform?  Preferably an 8ch one, but any would do.  

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  • Neither the GUI or CLI report receiving any signals from the radio.  

    What am I missing in the waveform?  

    I haven't attached sensors yet, do they need to be present for it to analyze the PPM stream?

  • the attached picture is the closest approximation to the PPM waveform that I have made.  It has 8 pulses of 1.5ms each, separated by approximately 0.250us.  The pulse sets are delimited by a single 3.75ms pulse.  

     

    Should that timing be read by the APM firmware?

     

    I have it going into pin PL0 on the atmega2560.  There is a solder jumper that could connect it also to PL1, should that be shorted?

    tek00003.png

    https://storage.ning.com/topology/rest/1.0/file/get/3692287417?profile=original
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