3

I was wondering if it is possible at all the manipulate the radio hardware on the device to transmit an FM signal on a specified frequency. As far as I am aware, the phone uses Bluetooth radio, it uses 802.11 radio, so would it not be possible to adjust the power output of the radio device to transmit at frequencies of 87.5–108.0 MHz?

If anyone has any documentation/research papers/guides into this area, please let me know. Is there any generic radio support in the SDK? Because my thinking is, if we can use Bluetooth and Wifi in the SDK, why can't we adjust configurations accordingly?

Cheers,

Tim.

Jonas
  • 121,568
  • 97
  • 310
  • 388
Tim
  • 8,932
  • 4
  • 43
  • 64
  • 3
    How's your RF electronics theory? Try Google on the subject to find out why the circuitry needed to broadcast at GHz frequencies is useless at 20x below that. Aside from that, these things use dedicated chips which 'tune' digitally to allocated channels. Plus broadcasting at FM frequencies is illegal in very many parts of the world. – Squonk Jun 09 '11 at 22:54
  • Thanks for the response. In the UK it isn't illegal to broadcast FM frequencies in short range. – Tim Jun 10 '11 at 11:53

2 Answers2

2

I was wondering if it is possible at all the manipulate the radio hardware on the device to transmit an FM signal on a specified frequency.

AFAIK, most (if not all) Android devices ship with hardware radios, not software radios, and therefore this would not be possible.

CommonsWare
  • 986,068
  • 189
  • 2,389
  • 2,491
  • It was just an idea I thought, and I thought someone on here would have some information on it. Thanks for the response, least it is something Android handset developers should consider. Cheers. – Tim Jun 10 '11 at 11:54
1

It looks like many of this next generation of phones have chips that support FM transmission ( ie Sony's Xperia line utilizing Texas Instrument's Omap chips ) but the FM transmitter is not supported. I can only speculate on the reasons. Extra internal components/shielding required? Interferes with the phone's other electronics making it prone to crashing? Not user friendly? Needs a custom antennae in the headset plug?

Sony released their modified TI drivers... http://developer.sonymobile.com/2012/03/07/fm-radio-module-released-as-open-source-and-sensor-hal-updated/ and the TI code to control the transmitter is among the lower level routines... but I didn't notice it carried up to the Java interface level.

Would be interesting to try it out....

JJones
  • 802
  • 7
  • 7