The FM radio receiver is built in to the same chip that does the WLAN and BT. It is actually a third radio in those chips. This is true of the Droid X, which uses the TI WL1271 BT/WLAN/FM chip, and many of the HTC and Samsung devices use the Broadcom BCM4329, which also has BT/ WLAN/FM.
I think vendor-specific HCI commands are used on the BT UART interface to tune the radio. With some kernel hacking, it should be possible to snoop the HCI commands. The FM audio out is an analog stream that is fed into a mixer, but it is also possible to get digital audio out over i2s, and probably also the HCI interface, but I dont think that method is used. There is no FM standard API in Android, but it would be nice to create one.... -Howard On Dec 19, 3:14 am, wolf <[email protected]> wrote: > do you can make me an a example code ? and a sketch with a example > phone how it works ? can i use the bluetooth as an antenna (yes i know > it's have own API and it's works on 2.4 Ghz and the radio usually 87.5 > to 108.0 MHz) ? do you know how to use the headphones as antenna or wi- > fi or whatever ? what do you think about this? do you have το suggest > me a site ? thanks mr bob for your time, you help me a lot!!!! sorry > for my bad english ....... p.s. i am search wikipedia and other sites, > i have make a simple plan. Do you work on FM Radio ? and how it's > works low level phone access ? hmmm... maybe can help me very > very ...... > > On Dec 19, 1:44 am, Bob Kerns <[email protected]> wrote: > > > > > Me, either. But I'll speculate as to how it works. > > > Phones are radios. The radio signal is processed and decoded into > > audio, and fed into the audio streams. The mechanisms for this are > > open source. > > > The FM radio signal is a radio signal that is processed and decoded > > into audio. I bet it works much the same way. > > > So, if you're serious about figuring it out, I'd start by going and > > learning how the low level phone access works (i.e. how the audio is > > routed from radio to audio mixer). That part is open source. > > > Then I'd start reverse engineering, and find what calls the FM radio > > app is making that are similar to how the phone works to set up the > > audio stream for phone callls, and from there, I'd look for what's > > different, that might be how it tells the radio what stream to route > > to where. > > > I doubt there's an easier way to do it, if that's how it's set up to > > work. If, on the other hand, it's just exposed as a separate device, > > I'd look at what device drivers are added to the kernel, and look to > > see how the FM Radio app turns it on and accesses it. (And the FM > > Radio functionality does have to be specifically turned on by the app. > > I'm guessing it's normally disabled due to battery consumption, but I > > don't really know). > > > On Dec 18, 1:19 pm, Mark Murphy <[email protected]> wrote:> On Sat, > > Dec 18, 2010 at 4:13 PM, wolf <[email protected]> wrote: > > > > thanks again mr bob, and how i can to view the code from FM Radio app? > > > > I am not aware of any "FM Radio" apps for Android that are open source. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
