Help needed in problem with unknown baud rate..

Hello everyone,
I’m working on interfacing a GSM cellular phone with computer through AT command. The phone I have is a k300i from sony ericsson.. I managed to interface it with PC and was able to read messages in PDU format. To do this, I used teraterm virtual terminal because I’m using windows 7 and hyperterm didn’t work on my PC. But I made a little mistake. I’ve set the baud rate of the phone with [AT+IPR=*****] command and probably that shut down the auto baud rate detection system of phone.
However it was a week before. Then I got busy with exams and now when I started working again and I discovered that I forgot the baud rate I set a week ago.:roll: I tried with some different values but the interfacing process isn’t working… :sad:
So what should I do now? Is there any way to return this auto baud detect system? Please help.
Thanks in advance.
Rocket Scientist


Pin config. of k300i: (4=Tx 5=Rx 10=GND 11=Vcc)
max 232 IC was used in interfacing circuit.

Measure it with a scope

but how?? the phone isn't giving any response...

Try to reset the phone to default configuration (from menu option). That should restore initial settings

Hello cristianp,
Thank you very much for helping me in finding the solution out. I followed your advice and now my phone is working again.
Regards,
R.S.