[K12OSN] Linux Bell system

Jim Kronebusch jim at winonacotter.org
Thu Nov 10 16:57:41 UTC 2005

> So you are using cron to schedule bells and delivering the sound 
> (tones) via your in house intercom system - YES ?  Very smart.   How 
> did the intercom interface go ?  Any really old systems ?  You can 
> control alternate schedules and even fire drills and stuff YES ?

Looks like I was missing one piece.  I now added a daily restart of crond
after running the script to swap cron jobs.  I also am now adding more stuff
to play different start of day sounds (such as announcing todays schedule) and
different end of day sounds (say laughter and jubilation).

I wired an 1/8th male audio jack to a 3 prong male microphone jack and plugged
the microphone jack to our receiver for our intercom system.  So now the
computer is simply another microphone on the system.  Whichever cron schedule
is set for the day plays the selected audio tone over the intercom system.  I
can now simply SCP any audio file over to the system and play it on demand as
well at the command line with "play /path/to/audiofile".  This will be fun.  

Using the task scheduler from webmin makes a nice gui way to automate the
scripts ahead of time as well.

Never thought of using this for fire drills, I don't know what kind of rules
there are for that but I imagine this would have to be tied into the fire
sensing system and manual alarm boxes to be of code.

I hope the scripts and stuff above help.  Let me know if you have any other

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