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gr-rds

Decodes the data carried alongside broadcast FM — station names, traffic

What it does

Decodes RDS, the low-rate data channel on a 57 kHz subcarrier of a broadcast FM signal: station name, programme type, radio text, alternative frequencies, the clock, and TMC traffic messages. It also transmits it, which is where the module's name ends in "transceiver".

Why you would want it

It is the friendliest possible introduction to real demodulation. The signal is strong, always present, and the result is human-readable text that either matches what the station is called or does not -- immediate feedback that no weak-signal work gives you. As a first GNU Radio flow graph to understand rather than merely run, it is hard to beat.

Before it will work

Any SDR that covers the FM broadcast band and a couple of hundred kHz of bandwidth. A wire will do for an antenna.

How it installs

  • apt: gr-rds

Known problems

RDS needs a solid signal: a station you can hear through noise will produce partial or garbled text, which looks like a decoder bug and is not. The transmit side is real RF on a broadcast band and is not lawful to radiate in most places -- the module will happily generate it into a dummy load or a file, and what leaves an antenna is your responsibility.

Keeping it current

  • probe: apt policy
  • strategy: apt_upgrade

Where to get help with the software itself

Bastian Bloessl. GitHub issues at the URL above.

Source: catalog/packages/gr-rds.yaml