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problem in modem interfacing with microcontroller

Started by abhay April 9, 2007
hi,

i m interfacing GSM modem to my microcontroller.i need to send sms
through it.

i am using AT commands for that.the command to send sms (AT+ CMGS)
must
terminate with ctrl-Z.now in my program

AT , AT+CMGF = 1, AT+CMGS = mobile no. , "message to be sent " ctrl-
Z /
26 / ^Z

the problem is : I connect my microcontroller and then switch ON the
modem my program runs afterwards but SMS is not sent.but when i reset
my microconroller board the SMS is sent.
i am unable to find the reason.also i was suspecting the role of RTS
pin but online documents show that it shuould be set high once
only ....do i need to reset or do something with this pin when my
program runs ?

plz suggest some way . suggestions are also invited if you suspect
some other problem .