It’s Friday night at Adafruit, usually that means we take apart something… Here’s part I of reverse engineering a pager (m4v).
NOTE: Oops, I was tired. There’s a mistake in the video! The chip is a TA31149 4-FSK (not 31142 2-FSK), and I printed out the wrong datasheet. Still, its pretty much the same idea/chip, just follow the ’31149 datasheet for the correct pinouts, there are -two- serial lines for 2 bits of serial data. Sorry about that!
Here is the manual for the pager (I couldn’t figure out how to turn the damn thing on), the datasheet for the TA31142 (2-FSK decoder used in other pagers, note the front page pinout is completely wrong) and TA31149 (4-FSK decoder used in the pager) a nifty little text file and a thesis with details of the FLEX protocols