search

travisgoodspeed / goodwatch

Replacement board for Casio Calculator Watches using the CC430F6147
508 stars 55 forks source link

POCSAG/DAPNET Support #118

Open travisgoodspeed opened 5 years ago

travisgoodspeed commented 5 years ago

Use this issue to track development of a POCSAG receiver, intended for use on Dapnet at 439.9875 MHz.

Progress:

travisgoodspeed commented 5 years ago

Successfully decoding packets with some code that is far too ugly to commit! Next free weekend should see proper support in the main branch.

travisgoodspeed commented 5 years ago

The power situation is pretty dire: We spend 16mA while actively listening, exhausting the coin cell in only six hours! As a temporary solution, I'm exiting the pager app when no packets have been seen for three minutes. Later, we can match the transmitter's timeslot to sleep between packets, hopefully extending usage to more than a day.

travisgoodspeed commented 5 years ago

This module is still a work in progress, but documentation is up on the wiki. https://github.com/travisgoodspeed/goodwatch/wiki/POCSAG

As far as power management goes, it looks like we can definitely reduce consumption from 16mA to slightly more than 1mA by keeping the radio in IDLE except when periodically sampling for the 480ms preamble. This will also fix the LCD fade out problem on CC430F6137-based watches, and depending on the settling time, we might be able to get even better lifetimes by shutting the radio off entirely between preamble-samplings.

travisgoodspeed commented 5 years ago

Average draw is down the 4mA by polling for the preamble, and that might be made a bit list. We're up to 24 hours of battery life.