3 ms·

Any data broadcast potential there ? Localised FM data broadcasts might be fun to mess around with.

by tudorw 9y ago

LeonM 9y ago
You can, but it will be really, really slow. And one-way only of course. HAM operators have been using that since the 80's (maybe earlier?), broadcasting data, pictures (i.e. SSTV) or text (i.e. hellscreiber)
- aidenn0 9y ago
  FM radio is both wideband and very high power, so I imagine it should be able to get at least 100kbps if you replaced the audio with trellis-modulated data, though I'm sure the FCC wouldn't be very fond of that
lawlessone 9y ago
There is this https://en.wikipedia.org/wiki/Radio_Data_System https://en.wikipedia.org/wiki/Radio_Data_System In some cars i can see display of the song name. It's also possible to turn a raspberry pi into an FM transmitter. http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspb...
julianj 9y ago
I am curious if the FM chip is able to listen outside of the typical 88-108 MHz.
- Jeema101 9y ago
  Japan uses 76-90 MHz for FM broadcasting, so my guess would be that most might be able to go down to 76 at least.
mikestew 9y ago
Most certainly, it is what drove data to Microsoft SPOT watches: https://en.m.wikipedia.org/wiki/Smart_Personal_Objects_Technology https://en.m.wikipedia.org/wiki/Smart_Personal_Objects_Techn... I still have a few lying around, though the data service has long since been turned off. It was low-bandwidth, but suitable for stock prices, weather, and incoming-only text messages via (IIRC) MSN Messenger. Cell phones have since replaced the functionality, but I loved mine at the time.
lflux 9y ago
Yes, DARC is used to broadcast public transit arrival times over one of the public FM radio stations in Stockholm and Helsinki (and probably other places): http://www.windytan.com/2013/11/broadcast-messages-on-darc-side.html http://www.windytan.com/2013/11/broadcast-messages-on-darc-s...
reaperducer 9y ago
There have been several schemes over the years for using FM broadcasts for data. In the early 80's, you could hook your home computer (Commodore 64, etc...) to the headphone jack of a radio and late at night some stations would carry a program that would send data. It sounded a lot like an old-school modem. In the mid-90's I had a TV set-top box that gathered TV guide information over an FM data subcarrier. The company went out of business. These days, data over broadcast is done on TV channels instead of FM because the bandwidth is larger. There's one of these operating on channel 20ish in Houston. I have no idea what data it's broadcasting.

Any data broadcast potential there ? Localised FM data broadcasts might be fun to mess around with.

by tudorw 9y ago

Any data broadcast potential there ? Localised FM data broadcasts might be fun to mess around with.

You can, but it will be really, really slow. And one-way only of course. HAM operators have been using that since the 80's (maybe earlier?), broadcasting data, pictures (i.e. SSTV) or text (i.e. hellscreiber)

aidenn0 9y ago
FM radio is both wideband and very high power, so I imagine it should be able to get at least 100kbps if you replaced the audio with trellis-modulated data, though I'm sure the FCC wouldn't be very fond of that

lawlessone 9y ago

There is this https://en.wikipedia.org/wiki/Radio_Data_System https://en.wikipedia.org/wiki/Radio_Data_System In some cars i can see display of the song name. It's also possible to turn a raspberry pi into an FM transmitter. http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspb...

julianj 9y ago

I am curious if the FM chip is able to listen outside of the typical 88-108 MHz.

Jeema101 9y ago
Japan uses 76-90 MHz for FM broadcasting, so my guess would be that most might be able to go down to 76 at least.

mikestew 9y ago

Most certainly, it is what drove data to Microsoft SPOT watches: https://en.m.wikipedia.org/wiki/Smart_Personal_Objects_Technology https://en.m.wikipedia.org/wiki/Smart_Personal_Objects_Techn... I still have a few lying around, though the data service has long since been turned off. It was low-bandwidth, but suitable for stock prices, weather, and incoming-only text messages via (IIRC) MSN Messenger. Cell phones have since replaced the functionality, but I loved mine at the time.

lflux 9y ago

Yes, DARC is used to broadcast public transit arrival times over one of the public FM radio stations in Stockholm and Helsinki (and probably other places): http://www.windytan.com/2013/11/broadcast-messages-on-darc-side.html http://www.windytan.com/2013/11/broadcast-messages-on-darc-s...

reaperducer 9y ago

There have been several schemes over the years for using FM broadcasts for data. In the early 80's, you could hook your home computer (Commodore 64, etc...) to the headphone jack of a radio and late at night some stations would carry a program that would send data. It sounded a lot like an old-school modem. In the mid-90's I had a TV set-top box that gathered TV guide information over an FM data subcarrier. The company went out of business. These days, data over broadcast is done on TV channels instead of FM because the bandwidth is larger. There's one of these operating on channel 20ish in Houston. I have no idea what data it's broadcasting.