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QYT KT8900 radio data stream decoding — Parallax Forums

QYT KT8900 radio data stream decoding

JonathanJonathan Posts: 1,023
in General Discussion
Hi All,

Came into possession of a QYT KT8900 and am poking into it with an eye to use it for a repeater link with a Prop for a brain, of course. So, I put a scope on the data line from the mic and was surprised to see that it sends a non-stop data stream, not just when a key is pressed. I tried baud rates from 300 to 115200 and nothing but nonsense. So it isn't ASCII, at least I don't think so.

Does anyone have any idea about what protocol these might use? Or any insight into hacking these? At least the mic cord terminates in a SIP header, so very easy to connect the radio to a breadboard.

Thanks!

Comments

  • pmrobertpmrobert Posts: 673
    edited 2016-08-27 16:59
    I think the community at CHIRP chirp.danplanet.com/projects/chirp/wiki/Home has some working code for your device. It's open source so perhaps perusing their source may help you.

    -Mike
    Edit: that's wierd. The forum software appears to have initially eaten the 'o' in 'com' in
    the link. Fixed now, I hope...
  • JonathanJonathan Posts: 1,023
    Thanks Mike. Do you think the programming port would be using the same data protocol as the mic? If so, that would help. I'll dig into that, thanks.

    Jonathan
  • pmrobertpmrobert Posts: 673
    I do not know. As a first pass, I'd throw a logic analyzer on those lines, capture a decent sized sample and play with the analysis tools most LAs have.

    -Mike
  • JonathanJonathan Posts: 1,023
    The only LA i have is a propscope and I don't think it has any analysis tools. I'll dig out the LA board and see what's there. Would be handy to be able to send commands from the mic, although I have gotten a simple repeater going already.
  • pmrobertpmrobert Posts: 673
    Very cool! How do you have it set up? As a crossband repeater?

    -Mike
  • JonathanJonathan Posts: 1,023
    Nope, a UHF repeater with a standard 5mHz offset. I am using two of the KT8900, they were given to me, one for rx and one for tx. I have a small band reject mobile cavity filter which I am attempting to tune up well enough to use. I have auto cw id going and DTMF decoding. So I will be able to make a legal repeater. But, it would be really nice to tap into the data stream and then be able to remotely set an parameter that that can be set through the keypad.

    Thanks!

    Jonathan
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