[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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