[aprssig] OT1+ KISS firmware

Scott Miller scott at opentrac.org
Thu Jul 26 20:12:29 EDT 2007

The OpenTracker+ wasn't ever intended to be a general-purpose TNC, but 
the demodulator code has worked out well enough that I figured it'd be 
worth writing a KISS implementation.  It's now available for download. 
It's not going to replace your KPC-3+ (and probably not even a TNC-X) 
but hey, it's one more thing you can do with it for no added cost.

 From the OpenTracker mailing list post:


Ok, there's now a KISS firmware image available.  Load this up and it'll 
  throw out all the regular tracker functions and give you a dumb KISS 
TNC, with a whopping 210 byte packet buffer.

DTE speed is fixed at 9600 baud.  The TXDelay, quiet time, and DCD mode 
settings from the config program are used, everything else is ignored. 
The KISS TXD command (where the host sends the TXD setting) isn't 
honored yet.

I've been running it with UI-View32.  My test setup at the moment has a 
CD player piping the WA8LMF APRS test CD into an Agilent 8920A service 
monitor, which feeds an Alinco DJ-F1T handheld via a short coax cable at 
-30 dBm on 144.50 MHz.  I have to say it works better than I'd ever have 
expected from such a simplistic demodulator.  I'll have to get a count 
of total packets decoded and see how it compares to the T2.

One caveat - don't send it half a KISS frame, or it'll lock the buffer 
and wait forever for it to end, and won't receive anything.  I'll add a 
timeout eventually to avoid this.


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