[aprssig] Wanted: tone-based reset module schematics
Andy AB9FX
ab9fx at aprs.pl
Mon Feb 6 22:22:40 EST 2006
There is some project with DTMF control (reset TNC and more) working with SP6VGA-2 digi by SQ6ADE.
http://www.aprs.pl/ftp/dtmfd.zip
Comments are in Polish, so if you are interested in it, I can do translation for you.
73!
Andy AB9FX SP3LYR
----- Original Message -----
From: Brad [VE3BSM]
To: 'TAPR APRS Mailing List'
Sent: Monday, February 06, 2006 18:56
Subject: [aprssig] Wanted: tone-based reset module schematics
One of the digipeaters I upgraded to UIDIGI last summer had a small circuit card mounted in the TNC. I didn't pay much attention at the time, but it turns out to be a small reset circuit for the TNC. Basically, it listens on the audio input for a specific tone for 2 seconds, at which point it trips the reset line of the TNC. It's used to recover from a severe lockup of the TNC (which it turns out UIDIGI sometimes suffers from). I had to use it once recently and it saved me from a miserable hike up a snow-covered mountain.
I'd like to come up with something similar for the other digis I maintain. But I haven't yet found any schematics for anything *simple* that does the trick. I'm hoping maybe somebody here has some schematics, or a pointer to a site with some.
Failing that, when Spring comes I'll hike up the mountain and reverse-engineer what's up there, though that's not exactly my strong suit.
Emphasis on the "simple". This one uses a single tone and I seem to recall it had one IC (maybe two) and only a couple of discreet components. A DTMF decoder would do the trick (and be less prone to spurious resets, presumably), but I really don't have the ability to get into PIC-based designs.
Anybody seen anything like this?
Brad.
VE3BSM
------------------------------------------------------------------------------
_______________________________________________
aprssig mailing list
aprssig at lists.tapr.org
https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.tapr.org/pipermail/aprssig_lists.tapr.org/attachments/20060206/1de81cf7/attachment.html>
More information about the aprssig
mailing list