[maemo-developers] FM RDS data

[From: Simon Pickering]

> > I'm thinking of a small usage, a app that found the freest frequency 
> > (by listening fm with the transmitter) and change the frequency of 
> > transmitted music to the found one and send an rds signal by the 
> > transmitter, so you don't have to change frequency on your 
> car receiver (or everything else).

Great to hear this, I was thinking of trying something similar when I had
some time. The FM transmitter also has a basic receiver built in (afair from
the spec sheet), i.e. not the one that is built into the Bluetooth chip that
is used to listen to the radio, which I imagine is designed for just such a
usage (I think it just returns a signal level for each frequency, but I'd
have to take another look at the sheet to be sure) does anyone know if we
can access this at the moment?

Cheers,


Simon

> -----Original Message-----
> From: maemo-developers-bounces at maemo.org 
> [mailto:maemo-developers-bounces at maemo.org] On Behalf Of Martin Grimme
> Sent: 07 January 2010 07:23
> To: Benoît HERVIER
> Cc: maemo-developers at maemo.org; Aldon Hynes
> Subject: Re: FM RDS data
> 
> Hi,
> 
> yes, RDS PS and RDS RT can be modified. See
> 
> http://wiki.maemo.org/Documentation/Maemo_5_Developer_Guide/Us
ing_Multimedia_Components/FM_Transmitter_API_Usage
> 
> 
> Martin
> 
> 
> 2010/1/7, Benoît HERVIER <khertan at khertan.net>:
> > About FM and RDS modifying RDS signal transmited from the tablet is 
> > possible ?
> >
> > I'm thinking of a small usage, a app that found the freest 
> frequency 
> > (by listening fm with the transmitter) and change the frequency of 
> > transmitted music to the found one and send an rds signal by the 
> > transmitter, so you don't have to change frequency on your 
> car receiver (or everything else).
> >
> > I know that fm transmitter emit an rds signal ... but can 
> that be changed ?
> >
> > Does there is documentation about the fm transmitter and receiver 
> > somewhere on Maemo ?
> >
> > Thanks a lot
> >
> > 2010/1/6 Martin Grimme <martin.grimme at gmail.com>
> >
> >> Hi,
> >>
> >> the FM receiver's interface for RDS is exposed via sysfs. So any 
> >> application can read RDS data from it.
> >> The frequency bands the receiver is capable of are US/EUR (87.5 - 
> >> 108.00 MHz) and Japan (don't remeber, but I think starts 
> somewhere at 
> >> 70 MHz). A region switch in the driver (sysfs-Interface 
> again but as
> >> root) switches between the frequency bands.
> >>
> >>
> >> Martin
> >>
> >>
> >> 2010/1/6, Aldon Hynes <Aldon.Hynes at orient-lodge.com>:
> >> > I have been approached by a person interested in sending 
> data from 
> >> > a
> >> sensor
> >> > via FM to a cellphone which would in term transmit this 
> data to the 
> >> > Internet.  I am interested in figuring out if this is something 
> >> > that
> >> could
> >> > be done with an N900.  With that, I have a few specific 
> questions:
> >> >
> >> > First, can anyone point me to information about how to 
> >> > programatically receive RDS data?  I've read that the FM receive 
> >> > app is supposed to do
> >> that,
> >> > but I haven't managed to receive RDS data that way yet, 
> and I don't 
> >> > have
> >> the
> >> > source code.
> >> >
> >> > Second, does anyone have any idea what frequencies the 
> FM receiver 
> >> > can
> >> tune
> >> > into?  The programs I've seen have focused on the traditional 
> >> > commercial
> >> FM
> >> > band, 88 Mhz to 106 Mhz.  Can the FM receiver tune in higher or 
> >> > lower frequencies?  If so, what is the real frequency 
> range of the 
> >> > FM Receiver.
> >> >
> >> > Third, are there other data formats that can easily be 
> sent and/or
> >> received
> >> > from the Nokia phone?  If so, can people point me to any 
> of these 
> >> > other
> >> data
> >> > formats?
> >> >
> >> > Any help you can provide would be greatly appreciated.
> >> >
> >> > Aldon
> >> >
> >> > _______________________________________________
> >> > maemo-developers mailing list
> >> > maemo-developers at maemo.org
> >> > https://lists.maemo.org/mailman/listinfo/maemo-developers
> >> >
> >> _______________________________________________
> >> maemo-developers mailing list
> >> maemo-developers at maemo.org
> >> https://lists.maemo.org/mailman/listinfo/maemo-developers
> >>
> >
> >
> >
> > --
> > Benoît HERVIER - http://khertan.net/
> >
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