RDS

[Eric R]

Take a look at the schematic below for the Ramsey FM30. I thought that the intersection of C20 and D5 would be the best but it kills the output of the transmitter. I picked closest and easiest connection next and it was behind R21. It did work but not really well. Anyone else have a suggestion?


Attached files

[Steven]

I think your best bet would be the intersection of R12 and R39. That's the path of the signal that modulates the FM transmitter.

Another option may be a pin of U6, but the schematic you posted is too small to see what that is. The FM25B doesn't have an IC in that part of the transmitter.

Edit: After reading the circuit description from the FM30 manual on the Ramsey site, it appears the best injection point may be at the intersection of R10 and R5.

[Eric R]

Good call, Thanks!

Working pretty good.

PT change is instant but the Radio Text takes anywhere from 45 - 90 seconds or more after the text file has been updated and the miniRDS software has sent the info. I ask this because using it with LOR, a song could be near half way over before the radio display ever gets the update.

Is this normal?

[Steven]

Eric R wrote:

PT change is instant but the Radio Text takes anywhere from 45 - 90 seconds or more

I noticed that too. I suspect that because the RDS data rate is only about 1kbps, the radio text is not sent often simply because there isn't enough bandwidth. The other factor is that most car radios don't display the Radio Text. On others (like Toyota), the radios enable the "MSG" button when Radio Text is received, but you still have to press the button to see it.

For this reason, I use the Radio Text for information like our hours and website, and put the song in the dynamic PS.

[Eric R]

Radio Text seemed to work better for me than dynamic but I will give it another shot. I am using my sons Zune and I have not gone out to see what comes up in the car. Maybe that will work better.

I did notice that in dynamic, mode 0 seemed fine but the other modes didn't want to scroll. I will work with it some more and also check the car radio.

[Eric R]

Figured out the slow update issue. I was giving it too much signal. It is now updating as expected both after an update and when tuning into the frequency for the first time.

Final specs:

Ramsey FM30 with MiniRDS connected at the intersection of R5 and R10 as suggested by Steven. The resistor value is 22k and the pot is at the 10:00 position.

Adjusting the pot down: no data sent. Adjusting the pot up: slow updates and missing data.

Hope this helps the next person down the line!

I have not tested data in the car yet as the Zune looses connection with the RDS when I walk outside. I will need to reinstall my outdoor antenna for further testing.

[stanward]

Hello,

Are you sending artist and title track information? I was wanting to do that with RDS, but am not sure how to do it from the LOR end of things.

Thanks,

Stan



Eric R wrote:

Good call, Thanks!

Working pretty good.

PT change is instant but the Radio Text takes anywhere from 45 - 90 seconds or more after the text file has been updated and the miniRDS software has sent the info. I ask this because using it with LOR, a song could be near half way over before the radio display ever gets the update.

Is this normal?

[Eric R]

I have only tested it as far as listed above. I did install my outdoor antenna a little bit ago and plan on doing some more testing tonight. I might try it with LOR pending how things go with reception in the car.

[stanward]

Eric R wrote:

I have only tested it as far as listed above. I did install my outdoor antenna a little bit ago and plan on doing some more testing tonight. I might try it with LOR pending how things go with reception in the car.

Hi Eric,

I was wondering if you would be willing to post just what exactly you are doing? I'm pretty dumbfounded when it comes to this RDS stuff, and wanted more insight on what others were sending over (what text do you plan on displaying).

Thank you,

Stan

[Steven]

stanward wrote:

and wanted more insight on what others were sending over (what text do you plan on displaying).

My (very incomplete) survey has shown that most car radios either do not display the RT (Radio Text, the 64-character field) or require you to press a special button to see it. Therefore, I only use dynamic PS (8 characters at a time) to display the song info.

Here is an example of what I display:

Jingle Bells Robert Goulet
Decorations Bob Rivers
The Cristmas Song - Toby Keith
Carol of the Bartenders - Bob Rivers
O Little Town of Bethlehem - Bob Rivers
Rockin' Around the Cristmas Tree Dion
Winter Wonderland - Toby Keith

...and more. Notice that I have misspelled "Christmas". This is because PS is limited to 8 characters, and if spelled correctly, Christmas comes out as:

Christma
s

This is a snapshot of what I did at one time. I have since found that separating the song and artist with a '-' does not usually look good when displayed 8 characters at a time.

Also, let's realize that the #1 purpose of this RDS stuff is education (for us to learn the technical details). In other words, it won't add that much to your Christmas display because depending on the type of visitors you have, less that half will probably have RDS-capable radios in their cars. (Perhaps more for me here in Silicon Valley ) Also, a typical visitor will (hopefully) be too distracted to look at their radio!

There is another RDS thread around here somewhere that describes the BAT file and the command line to use in the sequences.

[Eric R]

stanward wrote:

Hi Eric,

I was wondering if you would be willing to post just what exactly you are doing? I'm pretty dumbfounded when it comes to this RDS stuff, and wanted more insight on what others were sending over (what text do you plan on displaying).

Thank you,

Stan

Stan,

Steven pretty well summed it up. While I want to test it with LOR, my plans for now are simply a greeting or thank you for my visitors.

Testing didn't go well the other night. I get all the data on my sons Zune but none in the car. I am sure it is a tuning issue so on my next day off I will place a wireless camera in the car so I can watch the radio while in the house making adjustments. The running back and forth thing is for the birds and the local junk yard wanted $100 for a radio.

[jstein]

good idea about a camera. ive been trying to figure out a way so i dont have to go back and forth but i have enough camera wire to run one. Great idea!!!

[stanward]

Steven wrote:

My (very incomplete) survey has shown that most car radios either do not display the RT (Radio Text, the 64-character field) or require you to press a special button to see it. Therefore, I only use dynamic PS (8 characters at a time) to display the song info.

Here is an example of what I display:

Jingle Bells Robert Goulet
Decorations Bob Rivers
The Cristmas Song - Toby Keith
Carol of the Bartenders - Bob Rivers
O Little Town of Bethlehem - Bob Rivers
Rockin' Around the Cristmas Tree Dion
Winter Wonderland - Toby Keith

...and more. Notice that I have misspelled "Christmas". This is because PS is limited to 8 characters, and if spelled correctly, Christmas comes out as:

Christma
s

This is a snapshot of what I did at one time. I have since found that separating the song and artist with a '-' does not usually look good when displayed 8 characters at a time.

Also, let's realize that the #1 purpose of this RDS stuff is education (for us to learn the technical details). In other words, it won't add that much to your Christmas display because depending on the type of visitors you have, less that half will probably have RDS-capable radios in their cars. (Perhaps more for me here in Silicon Valley ) Also, a typical visitor will (hopefully) be too distracted to look at their radio!

There is another RDS thread around here somewhere that describes the BAT file and the command line to use in the sequences.

Hi Steven and Eric,

Please forgive me of being such a rookie. I was wondering how you (steven) are sending the data over with the LOR sequencing? I am awaiting for EDM to come out with the RDS version of their FM transmitter. I just learned what RDS was 2 weeks ago!

Even tho visitors won't be able to see the text on their radio(s), I still want to do something like that. Great cool factor and a totally awesome learning experience! Are you using Vixen to send text to the RDS or using the miniRDS software to do that?

Is the "other RDS" thread on this LOR forum, or is it on DIY or PC?

Thanks again!

Stan

[-klb-]

LOR 2.1.6 has the ability to run a batch file at the start of each sequence. The general idea is that that batch file changes the data file that the RDS utility uses to send text... The Mini RDS board has a software package that has several ways to get the data, and the package takes care of all the signalling details to the mini RDS itself... I believe you can even have it schedule the sources. So during the day, the RDS software can get data from Zara Radio about what is playing, but during show hours, go to a text file (populated by the batch file, that was launched by LOR).

[stanward]

Wow, that is great information! Thank you so much. I just hope EDM will build and deliver the RDS-equipped versions of their FM transmitter.

Stan

-klb- wrote:

LOR 2.1.6 has the ability to run a batch file at the start of each sequence. The general idea is that that batch file changes the data file that the RDS utility uses to send text... The Mini RDS board has a software package that has several ways to get the data, and the package takes care of all the signalling details to the mini RDS itself... I believe you can even have it schedule the sources. So during the day, the RDS software can get data from Zara Radio about what is playing, but during show hours, go to a text file (populated by the batch file, that was launched by LOR).