[usa2003ardf] Transmitters

[Matthew Robbins]

Jerry,

    I was cutting the grass today thinking about your project.  That's 
always a mistake, but...

    I wouldn't do this if it added any complexity to the controller, but... 
If the microcontroller has a voltage A-D converter built-in, you should 
consider having the box transmit its battery status (say its voltage) just 
before the id.  The idea would be to give the event managers a way to know 
the battery was failing.
   Another thought I had was to have a redundant battery system.  Say enough 
for twenty minutes or an hour.  If the controller could recognize that the 
primary battery had failed and the secondary battery was being used, it 
would be able to send a code in the ID that would let people know the 
secondary battery was being used so they could get out there and fix it 
before it went off-the-air.

    I can't say either of these ideas is any good.  Where I work, we have to 
be really careful of what we call "requirements creep".  You keep wanting to 
add features that don't contribute to the primary function, and they end up 
hurting reliability or making it cost more than it should.  You can debate 
all day about whether "an improvement" is useless gold-plating or an extra 
feature that will really help out.  Is it better to have two bad batteries, 
or to have a single good battery?  Is it better to know the voltage status 
of the battery, or just know the battery isn't going to fail because you 
know it's a good battery?   So I'm recommending that you consider these, but 
do what you think is best.

(My vote is for the voltage to be transmitted just before the ID.  That will 
let the organizers know everything is okay, and will give them some warning 
if there is a problem.)

Matthew
AA9YH

_________________________________________________________________
Add photos to your e-mail with MSN 8. Get 2 months FREE*.  
http://join.msn.com/?page=features/featuredemail