Developer
Since i got my new 2.4ghz spektrum radio (I FALL IN LOVE) i always wonder how the daughter receiver send data to the mother, maybe PPM? mmhh not! With a little help of an oscilloscope i started to reverse engineer the protocol used, well i saw only steady digital signal with lows of 8.6 useconds, that responded to the movements of my radio, so i quickly realize that is some kind of serial communication, and i did the calculations (1000000us/8.6us=116279bps) and i thought that maybe the serial speed was 115200bps. So i attached my FTDI cable and start analyzing the data, and i got this:Spektrum daughter board is sending 16 bytes of information using a serial com. running at 115200bps. As you see in the picture above, the two first bytes are the preamble or sync bytes (0x03, 0x01). The data comes in integers that response precisely in the order is labeled in the picture...So Paparazzi users this is a way to switch 2.4ghz (only in American), the back of my Specktrum radio says: "NOT FOR USE IN EU", uuh!I hope somebody can do something usefully with it, enjoy!
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  • I was finally able to find a way to connect my arduino duemilanove to the spectrum receiver. I was also able to make sens out of the transfer protocol, an wrote a library for pulling the different channels from the signal.

    The library and a step by step guide on this topic may be found in this blog post:
    http://www.dogfight.no/2011/01/spectrum-receiver-satellite-to-ardui...
    Spectrum receiver satellite to arduino duemilanove - Finally, it works!!
    I'm not sure where I first read about the concept of using the spectrum satellite receivers to read all the DSM2 channel signals through onl...
  • My Spektrum DX8 digital receiver has a 3.3v (orange), ground (black) and data (gray) line.  The data seems to be at 115200 baud and is producing a different stream of data.  I have not been able to work out witch bytes are witch controls. 

     

  • This is just the coolest info ever.  I've been looking for this for a time. Thanks.  I'll try it on my 8 and see what I see.

  • Here we go, this post describes how to decode and bind a Spektrum satellite RX.

    http://www.rcgroups.com/forums/showthread.php?t=922566
  • Did anyone ever figure out how to tell the satellite to bind over the 3 wire link?
  • Developer
    I have found another signal port. I will try it... and has tx/rx
  • Developer
    bGatti,

    Is just a preamble. The bind is another process that tune the devices to hear only our radio.
  • How do we handle the binding aspect of this connection? Any input on that? Thanks.
  • This is really interesting, thanks Jordi.

    Mikado is going to release a new version of their 3-axis stabilization system for model helicopters that uses a Spektrum satellite receiver only. It's called the Mini VBar.

    The Spektrum radios are sold in the EU as well but they seem to be limited in the output power.
    http://mikado.e-vendo.de/imgmi/download/mikado_infoflyer2009.pdf
  • Developer
    Oh that's nice! The transmitter has a port for the "buddy cable" but is PPM, is easy to decode but i prefer serial.
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