[aprssig] Wanted: tone-based reset module schematics

Gregg Wonderly gregg at wonderly.org
Tue Feb 7 11:46:55 EST 2006

Wes Johnston wrote:
> I can see that you'd want to know when or how often it resets... so when
> you design around your failsafe... when the 555 timer times out and
> asserts the reset, have it assert the reset for 5 seconds, and during
> that time, have it play a 1khz tone and key the PTT.  When you hear the
> 5 second beep on air, you know it has reset.  Not that anyone actually
> listens to packet channels for extended periods.  Alought I sometimes
> decode psk31 by ear for fun... lol.
> Seriously, another way to keep tabs on resets would be to get an electro
> mechanical counter (one pulse per count) and hook that to your reset
> line.  Then when you visit the site you can see how many times it reset
> since your last visit.

The other way is to use a micro controller to do the counting and tie a serial 
link from the uC to the TNC and beacon the count as a status packet.

Gregg Wonderly

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