[Az-Geocaching] Amateur Beacon / GeoCache..

[C. Sullivan]

On Thu, 18 Apr 2002, Brian Cluff wrote:

> This sounds pretty sweet!  How much did it cost to put something like that
> together?

The "prototype" (more on that in a minute) is a BASIC Stamp PIC.  They
cost around $40.  That provides the "intelligence" behind it.  The RF part
is a crystal oscillator (cost: $4) and a small signal transistor and a
couple of chokes/caps to act as a filter to keep the signal clean
(think Chebyshev).  The solar cells and the AA batteries were both
"surplus junk" I had lying around.  I suspect that one could probably put
the whole thing together for around $60, even buying parts new.

I've decided going to make a new one for the final cache.  Rather than use
a whole BASIC Stamp, I plan on just burning a PIC-16 chip and wirewrapping
it up on a small breadboard.  I may (if I can ever get this stupid
photoetch stuff working right) etch a real PC board and make it all neat.

I'm still working on some of the logistics on the cache canister
itself.  I may upgrade to a gallon can, and mount the solar panels on the
lid.  The prototype can has the transmitter mounted to the bottom of the
can and the wire antenna leading out of the bottom, with the solar panels
kinda half-assed attached on the side.

I can't find my digital camera, so I'm having to take "normal" pictures
and get them developed.  When I get those back, I'll have a web page up on
the "Canned Ham" Geocache.

Oh, and I added a new feature to the prototype: a thermister to take a
rough temperature reading.  Ah, creeping featurism.

I'm considering offering this as a kit, with a preprogrammed PIC-16 chip
and a professionally manufactured circuit board, if there's enough
interest.  At minimum, the webpage will have enough info that it could be
duplicated easily by somebody with entry-level electronics skills.

Hmm.. MCW using an FRS radio?  With it's own GPS reciever?  Nahh.... maybe
one with an APRS node inside?  *chuckle*

-Fedl