T230 direct interfacing with microcontroller

i am seriously not sure.. because USB.. well yeah modem is there in Z550i... but are USB operated not serial. so might be changes in configuration.
I think this page might be of some help to you..
Sony Ericsson Docs and tools for developers

i saw the pdf files they r gud.why the modem wont work if we convert rs232 to USB signals.Does it need handshaking signals.

I really don't know about this.. that you need to find out.

thanks for ur help friend i would definitely let u know if i get a lead

hi friend
i am planning to buy a DRS-11 serial cable for the phone.If the at commands works
then how should i interface controller with the cable.how to power up the cable?

check the cable on hyper terminal first. if it works then you can use simple RS232 interface... if possible test it on the shop so you shouldn't be wasting your money

how to power up the cable if i interface with controller?

first check it with hyper terminal if it responds you that means there is nothing more than just basic three connections are needed which are TX,RX and GND. also check the line status using some kind of serial monitor software.

hi
if i set off hardware control and try the at commands.will it work friend?

keep Flow Control as "none".
9600 8-n-1 connection...