gsm modem with 16f877a

[kumara]

dear friends
i want to interface M1206B gsm modem with pic 16f877a.modem with pc ok.i can send sms using hyperterminal.pc with pic ok i can display "at"
but pic and modem not suport.i have chang baundrate but donot work.i have find som post but i can't do it.please help me
thank you


' Initialization
TRISB=%00000000
PORTB=%00000000

'Definitions
DEFINE OSC 4
DEFINE HSER_TXSTA 20h
DEFINE HSER_RCSTA 90h
DEFINE HSER_BAUD 2400
DEFINE HSER_SPBRG 25

BEGIN:
PORTB = 0
HIGH PORTB.7
PAUSE 1000
LOW PORTB.7
HIGH PORTB.6
HSerout ["AT",13,10] 'TEST COMMUNICATION
HSERIN 5000,begin,[WAIT("OK")]
HIGH PORTB.5
PAUSE 500
GOTO begin

'END
End

[kumara]

any body help me..

[Ioannis]

1. Is your modem communicating with a PC at the specified speed? You seem to use 2400 baud rate...

2. Do the trick with a second serial port, two resistors (experiment from 10K down to 1K which ever works) to pick the Rx and Tx lines an monitor on a PC terminal. You will see if the commands are received and what the modem answers.

3. Post the results to check here.

Ioannis

[kumara]

1.it's works 2400 boundrate with pc.

2.i can't undertand this trick.

[Ioannis]

Modem PIC
Tx -----------X-----------------Rx
Rx ------X----|-----------------Tx
| |
1k 1k
| |
PC |----|
Rx-------X---X

Hope this helps you understand.

Ioannis

[kumara]

Mr Ioannis now i can send sms (i have 1 mistake rx and tx chang)but now i want to do read sms and high led.please help methank you