Good point about placement. I designed this in a hurry; <2 weeks
between start of design and receiving boards from Gold Phoenix in
China. I will post a tutorial, but I'm looking for jobs right now so
that will have to wait a week or two. It's a CR1220 battery. I ordered
50 of them from Brooklyn Battery Works for $25:
http://www.brooklynbatteryworks.com/.
They are rated for max pulse current of 5 mA, which is exactly what
the blue LED's are sinking without a current limiting resistor. As a
side note, blue LED's and 3 v batteries are one of a few combos you
can get away with not using current limiting resistors. But, you
should still use them anyway, so don't follow my example. The MSP430
current draw is ridiculously low, that's why they're used in lots of
battery powered applications. Not the fastest processor in the world
(<20 MHz, ~4 cycles/instruction), but very handy for low power stuff.
On Mar 18, 11:45 am, "Ronald \"Monty\" Montemayor"