jschnurr wrote:did you use an AVR or PIC?
PIC. Can you get 12 I/O pins on an AVR for $1? I have no idea.
I suppose it's simple enough, but I'm just curious how you filtered and stabilized the signal before feeding it into the microcontroller...
You're right... it's so simple I'm not going to waste your time by telling you how I did it. That's how simple it is! The code is even more trivial: two finite state machines, one to bang through the digits and the other to count the blades. Plus some 31 bit integer arithmetic.
photofly wrote:It's a $1 4.000 MHz crystal.
Pshhh, you could get 11 for that price
here.
Handy. If you live in Bangkok. If you live in Toronto however and you want one this afternoon (as I did, back then) then you'll pay $1. Which is why I described it as a $1 crystal.
Here they're even cheaper:
http://www.aliexpress.com/item/Free-shi ... 94570.html
photofly wrote:No extra switches- this is about minimal components, and three position switches are $0.70.
Would
$0.15 be too much?
One thing I have learned is never to buy cheap connectors, cheap switches, or knock-off semiconductors. They *always* give you more trouble than they're worth. Plus I'm also out of pins on the microcontroller and I can't be bothered to use a bigger one or do some crazy charlieplexing stunt to suit the few people who both have three blades and are too dumb to multiply by two and divide by three. Soz.
Right back at you.
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.