Getting jiggy with RDS

October 21, 2011

After recently acquiring a new FM transmitter from EDM Electronics, I sat down to explore the RDS feature.


RDS logo

For the unitiated: RDS is an acronym for Radio Data System. It’s basically a simple communication protocol for sending digital information within an FM broadcast.  You know those car stereos that will often display the name of a song and the artist singing it?  RDS makes that possible.

There is a dedicated software application that enables RDS data in my specific transmitter. As a protocol, it’s entirely dependent on both the sender and receiver to implement the features of RDS. While there are interesting elements to the RDS protocol, I’m most interested in what’s useful to me and the light display.

RDS features have code names.  The code names that interest me:

  • PS – “Program Service” is an 8-letter term that identifies an FM station.  Usually a station’s call letters are involved, i.e. KIRO97FM. I don’t *have* call letters, so I should probably make some up.  This is, so maybe WGLC or KGLC?  Guess I could get away with that, even though this station or that station might already be using them.
  • RT – “Radio Text” is (up to) 64 characters of free-form text. On many receivers, it will often scroll across the display.  This is usually where the song name and artist name come from.

So, how should I use RDS?

My initial thoughts were to use RDS to communicate text information about the light display and show while it’s running.  Because, well, that makes perfect sense.  But should I be limited to just that?  What else could I do?  Turns out, I have a bunch of ideas.

  • Guilt-free advertising – not the kind that makes money, but more public-service-announcement type stuff.
  • The website – remind everyone of our favorite site on the Interwebz,
  • Fun facts – details about the display and lightshow that would delight passers by of all ages!

Actually, there is one idea that I think would be *really* cool — integrate Twitter. 

In case you are unaware, you can get late-breaking news about the display by following @greenlakexmas on Twitter. It’s where I send out status messages about the display, interact with a lot of people who have seen the lights, and generally ramble on and on about my sickness hobby.

Suppose someone could mention @greenlakexmas in a tweet and have the message replicated out through the radio station?  Someone is watching the lights and sends a tweet “wow, the lights are awesome!” and it displays on the radio while they’re watching it.  Hmm, that sounds interesting.

But there are obstacles to making this reality:

  • Tweets are 140 characters. RDS Radio Text supports 64 characters.  Truncated messages aren’t fun for anyone.
  • Twitter is a pure passthrough, so anything goes. I don’t care to have profanity or whatnot re-published through the esteemed airwaves of WGLC.
  • Maybe nobody really cares.

Difficult problems, but not enough to keep me from trying this.  No promises, but I am going to explore this further.

Comments?  Just drop them on me @greenlakexmas on Twitter.

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