On 20/04/2011 21:34, Richard Prosser wrote:
>> I want to build a small device that can send a wireless signal to a Blue=
tooth cell phone. I can use a Bluetooth module to generate Bluetooth signal=
, which the cell phone can definitely receive. But it will be costly and th=
e module will consume too much power, is there any way I can create some si=
mple and low power rf signal and the cell phone can detect?
>> >
>> >  Thanks in advance!
>> >
>> >  John
>> >  --
> John,
>
> Probably not. Bluetooth does a lot of frequency selection etc. as well
> as a fair bit of handshaking&  decoding to communicate.  If the
> cellphone has an FM radio built in, that would be a far simpler&
> cheaper solution.

I used an 8 Euro 3.5mm jack in "iTrip" type FM transmitter. added=20
resistor to varicap on the VCO and connected a PIC based RDS encoder.=20
Picked up the 19kHz pilot from the "itrip" IC to "sync" the approx 56kHz=20
RDS carrier.

Phone able to display messages on FM Radio app (i.e. PC playing WinAmp=20
and MP3 Tags sent via RS232 to PIC RDS encoder.

There is also RDS user data, depending on phone you may be able to write=20
an application to read it. A PC with FM radio and add-ed on RDS decoder=20
with serial port was able to read the "user data". RDS data rate is low=20
as entire carousel is 1180bps.

Bluetooth and WiFi are very complicated, but you can get modules with=20
their own CPU and RF part that implement a simple interface, possibly=20
with 115kbps serial (via USB or RS232).

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.