Help me about communicating PIC with cellular phone...

[sayzer]

Also, is anyone else thinking about doing some search?

This forum has so many examples that most of the time makes me surprised.

What a treasure we have here!



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[dhouston]

Try cross-connecting TX & RX. That is, PIC-RX to Nokia-TX and vice versa. If you need to invert the logic (likely), see...

• http://www.picbasic.co.uk/forum/showthread.php?t=4778

or you could use two other of the PIC's pins and use SerIn & SerOUt so you can set the logic to inverted.

If the Nokia uses RS232 voltage levels (unlikely) you need current limiting resistors in the TX & RX lines. See the PBP manual pages for SerIn, SerOut.

[d_hamen]

Yes I had cross connected RX and TX of the phone and pic. I don't think the problem is because of it.

Nokia is working with TTL Logic so it gives high for 3.3v (so 5volt too) and low for 0 volts; So I think max232 is not needed to use here. Because it is using for RS232 which is working with 12Volt.

[dhouston]

Yes I had cross connected RX and TX of the phone and pic. I don't think the problem is because of it.

Nokia is working with TTL Logic so it gives high for 3.3v (so 5volt too) and low for 0 volts; So I think max232 is not needed to use here. Because it is using for RS232 which is working with 12Volt.

You still need to invert the logic. The PIC UART is uninverted. You either need to use SerIn/SerOut so you can invert in your firmware or you need to add two inverters (e.g. using the comparators as suggested in the link I gave earlier).

I'm not sure what you mean by "so 5volt too" but 3.3V is inadequate if you are using the PIC at 5V Vdd. Port C has Schmidt Trigger buffers which need 0.8*Vdd for a logic High (0.8*5V=4V). If you use SerIn/SerOut or DebugIn/Debug on pins that have TTL buffers, 3.3V should be OK.

[dhouston]

Are you sure about those 7250i pins? Everything I can find indicates the 7250i has USB and IR but there's nary a mention of a serial connection.

What is FBus?

[d_hamen]

FBUS is a protocol that nokia phones are using. It is same as AT commands but a bit complex.
I made the program as you said. but it doesn't work. FBus Rx&Tx means it is supported for serial connection for Nokia 7250i.


INCLUDE "modedefs.bas"

DEFINE OSC 4 ' Define clock Oscillator Frequency at 4Mhz
DEFINE HSER_CLROERR 0

OUTPUT PORTc.6
INPUT PORTc.7
PORTc = %00000000 ' Initial state of PORT C


Main:

' Make a call

serout2 portC.6, T9600, ["ATZ",13,10] ' Reset the phone
Pause 1000

serout2 portC.6, T9600, ["ATDT",34,"+905448515247",59,34,",129",13,10] ' Make a call for 15 sec.s 59 is ;
PAUSE 15000

serout2 portC.6, T2400, ["AT",13,10] ' Finish the call
PAUSE 1000

GOTO Main

END


Thanks...

[sayzer]

Himmm,

I now where this phone number comes from!

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