Momentum-Apps/README.md

Longwave Clock

This is a Flipper Zero app to receive and decode, or simulate, multiple time signal broadcasts with different protocols and time formats. For receiving via GPIO, an inexpensive receiver connected to a receiving pin is required.

Protocol support

DCF77 (DE, 77.5 kHz)

DCF77 is broadcasted from Frankfurt am Main in Germany (50.0155,9.0108) and requires an antenna tuned to 77.5 kHz.

• The radio transmission can be received all over Europe (~2000 km from the sender).
• 1 bit per second is transmitted by reducing carrier power at the beginning of every second.
• The transmission encodes time, date as well as catastrophe and weather information (encrypted, not decoded).

MSF (UK, 60 kHz)

MSF (Time from NPL/Rugby clock) is broadcasted from Anthorn in the UK (54.9116,-3.2785) and requires an antenna tuned to 60 kHz (as does WWVB).

• The radio transmission can be received over most of western and northern Europe.
• The transmission encodes time, date as well as DUT1 bits (difference between atomic and astronomical time).
• The app only supports the slow code at 120 bits per minute, of which only 60bits are encoded.

WWVB (US, 60 kHz)

WWVB is on the backlog for the Longwave app.

If you're based in the US and would like to help: PRs are welcome!