FM radio reception on neo/openmoko and some other questions

Doug Sutherland doug at
Fri Nov 9 20:41:24 CET 2007


The amazing thing about these Silicon Labs parts is that they require
almost no external components. For example the SI470x FM tuners
require a crystal and regulator, that is all, they can use headphone 
cable as antenna (as is done in most phones now), and they have 
stereo analog output and SPI interface for control and for getting 
the RDS/RDBS station identification and song info as text. Those
analog outputs could feed right into a TI PCM2900 and then 
you have a driverless USB audio FM tuner. Without access to 
SPI though a small microcontroller would be required. Could be
done with a $2 ARM7 or Cortex-M3.

I haven't looked too closely at the FM transmitters or receivers
yet, but I'll take a look and see what kind of external components
are required. So you're not even interested in FM tuner, just FM
transmitters and receivers? 

BTW I also have hardware based text-to-speech chips here 
that work really well and also require few components, they 
are UART input and analog and/or digital audio output, I have
already made one full speech synth for someone using them 
and have several more chipsets here.

I am actually more interested in speech based interfaces to 
phones and PDAs than the fancy GUIs, might be interesting
to bolt one onto a Neo at some point. My phone should 
READ web pages and email to me and whisper in my ear.

  -- Doug

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