Piclist,
        I got this message from a high school student I was helping for a
science project he was involved in. The project is a competition where
points are earned for performing a task ( I think it was to move a ping
pong ball into a cup) using as many changes of state (chemical to light,
light to electricity, etc ...) as possible. Read this, and if you can
believe it this kid came to me a year ago wanting to know what a
transistor does.  All I did was show him PIC web pages, helped him to read
schematics, and gave a few assembly tips, the rest was all youthful
curiosity, and persistance of effort on his part. There is hope for the
future yet.

        Matt

---------- Forwarded message ----------
Subject: How Science Olympiad is going...


Hi Matt:

I just thought I'd write you and let you know how our Science Olympiad
project with the PIC chip is going.  I finished the PIC chip circuit a
while ago and have been constantly changing it ever since.  Basically,
there is one main controlling PIC that runs all the motors and everything.
It is connected to a 4-to-16 Demultiplexer for output and a 16-to-4
Multiplexer for input.  Also, there is a two line serial connection to
another PIC to run an LCD screen.  The output demultiplexer's 16 outputs
connect to a stepper-motor-driver, motor drivers, servos, and some
transistor/relay circuits.  The stepper motor driver is really great
because it only uses ONE pin!  I made it with a 555 timer, decade counter,
and motor drivers.  Each motor driver runs 4 motors, so they are really
nice.  I also managed to get servos to run pretty well.  I can only run
one at a time the way I have it set up though.  The input multiplexer has
a lot of different things connected to it also.  There is a Photocell
circuit, Infrared Phototransistor circuit and Solar cell circuit.  I used
Op-Amps for those circuits and they work really well.
        I managed to get 10 messages on the PIC chip that controls the LCD
screen before the lookup table problem we encountered a while ago started
happening.  I made it so the LCD screen could output numbers too, and i
made a simple timer so the LCD can show how much time has gone by. Since
there are only 10 messages, the messages aren't very specific (ex.
"Running Module", or "Waiting for input" instead of "pumping iodine into
starch", or "raising ramp").  The serial communication is something like
1000 baud, i forgot exactly.  I could probably make it go faster but it's
fast enough for me right now so i left it alone.

Anyway, in the Regional competition in March our machine took 2nd place.
A maximum of 30 action transfers is allowed on your device and we had only
finished 20 for regionals so our score was much lower.  The "computer"
worked perfectly though, so I was happy.

We finished building all the action transfers for state and had a perfect
device, but at the competition there was one glitch.  In one of our
transfers, a servo opens a valve and salt falls through into a cup that's
on a lever.  one side of the lever gets heavy and the lever tilts just
like a see-saw and contacts on the other side of the lever touch each
other.. the computer reads it and goes on... Anyway, the servo opened the
valve and the salt didn't fall through, it got stuck somehow.  That one
glitch cost us a medal and we ended up 4th place.  We were all very upset
because we had dedicated every moment of that last month of our lives to
this machine, and we even stayed up until 3:45am the night before
competition calibrating things and got 30 min. of sleep.  Regardless, our
team did well in all of the events and won the competition, and we are on
our way to nationals in Michigan in 6 days.  The Mission Possible device
is now working PERFECTLY and we hope to get 1rst place in the entire
nation in that event.  We built a box around the thing and are shipping it
UPS in a few days.

I'll be sure to let you know how we do!  Thanks a lot for all of your help
with the electronics and learning the PIC chip.  I really appreciate all
the time you spent helping me.

Matthew