PIC to GSM

[Dennis]

Hi all

Anand , thanks a million for the tips , yes I'm aware of the FBUS and it's connector usually under the battery as well as built in modem on phone. I have been googlling like crazy for connection tips etc .... found some interesting stuff regarding a universal FBUS connectors (they call it an un-locker in most threads). As regards the 1208 there isn't too much about it and a PIC :-) . I really just chose that model since it was one of the entry level Nokia's which might possibly have allowed for the connection and still supported a serial cable connection.

What a mission though... unplug the battery pop the FBUS connector in and then still interface with a MAX which usually entails voltage changes 3,6V on phone side PIC side is 5V , yes I know it's just a little circuit and a few components. Just would be so much easier with connectors.
Solution of course is to buy a DKU-5 serial connector cable not so ?

Now what about other phones, Sony Ericsson or Motorola or Samsung etc ...
Would love to hear more about what people are using and how.

Falingtrea ..

Sounds like a nice project ... did you use a GSM module or an entire phone ?


Thanks guys I really appreciate the info

Regards

Dennis

[Dennis]

Perhaps it would be easier to mention the models I have so far.

How to you convert the voltages to suit the phone types ? Or should I just drive everything off the phone's battery ?

Some models I have available for to test with
Nokia 8210
Nokia 2110
Nokia N80
Samsung SGH-E700

Any suggestions ?

Kind regards
Dennis

[Gusse]

Hi Dennis,

Try to find some old Nokia Pop-Port™ phones, which have FBUS in bottom connector (i.e 7210 or similar).
Other option is to use even older DCT-3 phones (i.e. 6110 or similar). Shouldn't be too hard to find suitable.

All you need info about Nokia FBUS/MBUS cables
True +3V to +5.5V RS-232 Transceiver, MAX3221-MAX3243

Edit:
N80 is USB featured Pop-Port phone and therefore not usable.
8210 OK, but FBUS test pads under battery.

BR,
-Gusse-

[Dennis]

Thanks Gusse :-)

Exactly the kind of info I was looking for !

I am ok with getting to the FBUS connecter under the battery, but I am not sure how to power the phone/circuit !
Phone is at 3,6 Volts , PIC circuit is running on 5 Volts that's why I asked about whether or not to power everything from the phone battery ?

I have the MAX232N, PIC's , wires cable resisitors , all thats missing is the connection method :-) ?(so far)

Any suggestions would be great

Thanks
Dennis

[Gusse]

Hi Dennis,

Power the MAX232N from same source as your PIC. That is the easiest way, I think.

Then do some small modifications to your 8210.

Audio-to-Data from 2.5mm bottom connector:
1) Solder wires to Fbus Rx/Tx pads
2) Connect wires to 2.5mm audio plug (select suitable pins, proposal below)
3) Solder GND wire to 2.5mm plug
3) Put some isolator between PWB and spring contacts

Nokia 8210 Pin-out

1 - MBus
2 - GND --> MIC(-) & EAR(-)
3 - FBus-Rx --> MIC(+)
4 - FBus-Tx --> EAR(+)
5 - VPP

Then use 2.5mm stereo plug to make your own data cable to connect PIC to 8210. I would recommend to use coaxial (shielded) cable for connection to avoid GSM TX coupling to data signals.
I hope this will help you to continue your project

Edit: Image removed, but here is the URL Nokia accessories - schematics

BR,
-Gusse-

[Dennis]

Gusse ...

Thank you so much for the excellent info :-)
It seems the images or links aren't available :-( any chance of a URL ?
It certainly will help me continue :-)

Thanks once again

Kind regards

Dennis

[Dennis]

Gusse

Is this the image you are referring to ?
http://img99.imageshack.us/img99/429...onnections.jpg
Hope that helps others too

Kind regards

Dennis