I asked my little brother if I could destory is Harry Potter Powercaster toy. He agreed (it hasn't been used in years). What did I get out of it?
7 LEDs on a stick. Said stick waves back and forth. If you switch the LEDs on and off fast enough (and precisely/accurately enough), you can write words. Cool, I think. I want to hack that.
After some ripping apart, I get to the wires and such. It appears there are 8 wires going to the LEDs. Probably a commond GND and a +5V (or whatever) for each LED. Almost. It turns out there's a common +5V, and a GND for each LED. Oh well. It just makes things backwards.
The common positive lead goes into +5V (with resistor, of course). LEDs 1-7 go into pins 2-8. When the pin is LOW, the LED is on, when the pin is HIGH, the LED is off. Simple enough.
http://youtube.com/watch?v=mqfjrxsNJ54 (writes "HI")
http://youtube.com/watch?v=JN6xnTHElDQ (writes "WOOT")
Current poor, uncommented code: http://pastebin.ca/837605
I feel like this is okay progress for yesterday. Hopefully today will be more awesome.
TODO: Add a photodiode/phototransistor setup so I can accurately time the period of the arm. Figure out how to use the coils to make the arm swing. None of this finger crap. Add computer controlled-ness. Add horizontal/vertical scrolling. (Figure out how to encode the data better + Have the computer do the work)
EVENTUALLY: Make a giant one. Stop using tape to hold wires into the headers.
Alright. I'm going to go plug my soldering iron in.