Radio Data System (RDS)

Ɠαяєтн

Mae gen i C.L.A.P ei heintus iawn
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Dec 27, 2010
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235
Location
Landsdale, Perth, Western Australia
I was just thinking about using an Radio Data System for my show this year. This would encode data into the FM transmission for people to read on their radio's display. Information could include Show Name, Playing Now etc.


Has anybody used any software or hardware solution for this? I would be interested in understanding any experiences people have had with this good or bad.


I see Dave Pitts was talking about this with the Falcon Pi Player. I am looking for a solution to add to my PC to encode the audio output before it goes to the FM transmitter.
 

smeighan

Dedicated elf
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Jan 19, 2012
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4217 Greenfinch Dr CO 80126
the pi player has two plugins, one for EDM rds and one for vast 212 RDS.


You can also drive RDS from the xlights scheduler. Matt gave a talk about how you can send strings "wizards of Winter", "by TSO" for example and schedule those as part of your show.


I dont know how to do it on the other sequencers
 

damona

Full time elf
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Oct 23, 2013
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287
Think I will use the Rasberry PI itself as an FM & RDS transmitter, no extra h/w required.
 

fasteddy

I have C.L.A.P
Global moderator
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Apr 26, 2010
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Albion Park NSW
I really wonder what benifit an RDS transmitter has here in Australia as most radios do not have this feature.
I know it has a better uptake in the US
 

BradsXmasLights

WiFi Interactive
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Dec 23, 2010
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581
Location
Brisbane, Australia
My 2013 model car has RDS, which is usually abused by commercial radio stations spamming some BS rather than the standard Station Name / Artist / Song name fields.


But this had me thinking, Maybe I can spam messages via that method too!


"Merry Christmas"
"Connect to Wi-Fi"
"Get your Name in Lights!"


Or...
"Please dim headlights"
"Please keep street clear"
"More Parking around corner"

[SIZE=small]Although radio support would be very limited. Then they mightn't read it anyway. :s[/SIZE]


[font=verdana, arial, helvetica, sans-serif]How fast is RDS at updating on people's radios though? Is it instant? Or is there a some encoding delay? Wondering if I can synchronize the text to my matrix names too :D[/font]
 

BradsXmasLights

WiFi Interactive
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Dec 23, 2010
Messages
581
Location
Brisbane, Australia
Burnt up quite a bit of time this weekend on this.


First up, basically RDS is just a 57kHz signal 'on top' of the normal human audible broadcast. (Kinda similar to how DSL & standard voice phones can work together)


Anyhow, to get 57kHz from a PC you'll need a sound card that supports 192kbit audio on an analogue output. Most only do this on digital outputs, if at all. Then if you're running your PC audio via a mixing desk, or similar pre-Transmitter audio gear, you'll need to hope that this non-audible 57kHz frequency isn't high-pass filtered out.


Then technically to make matters worse, the 57khz sub-carrier signal needs to be in phase with the stereo pilot carrier signal. Now if my Stereo FM transmitter is generating this carrier tone when the RDS carrier is coming from elsewhere, I'm not too sure how well this is going to work? The RDS encoder apps I tested below can also generate a stereo carrier/signal (over a mono channel to a mono transmitter), but again I don't think this will work with a stereo transmitter.

So I ended up testing some software RDS encoders; Airomate (Windows) and Stereo Tool (on both Windows & linux) with a soundcard that I thought was capable of doing 192k on an analogue output. To cut a long story short, I got nothing working. :(

In the end, I've ordered an RDS encoder board that according to DIY christmas can be modded quite easily in to my vast FM transmitter.
http://pira.cz/rds/show.asp?art=micrords_encoder
 

Jamie

Lighting up the night.
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Dec 16, 2010
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399
Location
Warwick
This will be interesting to see up and running. You cettainly are a pioneer in these areas..
 

BradsXmasLights

WiFi Interactive
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Dec 23, 2010
Messages
581
Location
Brisbane, Australia
Well I got my RDS encoder board.


I hooked it up to my Vast FM02 and got it to transmit text - and a lot of interference. So I went to change the inter-connecting resistor that is soldered to one of the SMD legs on the vast board and then broke the SMD leg/track on the PCB. F********** :(



So now I need to buy a new transmitter!
 

damona

Full time elf
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Oct 23, 2013
Messages
287
Tested the raspberry pi as an FM & RDS transmitter. It does dot it, but it is a square wave signal from the reading I did, and hence can cause issues to other signals. Also a fair bit of noise. So for a play yes. I only tried with a wire as an antenna, if some one else could try antenna tuned to the FM signal being transmitted.
 
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