[SOLVED] GSM sim300 sends received data back on serial

[ashokb]

Hi,
From last two days i am working on (new bought) GSM sim300 module. I have connected it to my PC using usb to serial converter. Now, When i make call on the number which is inserted in module, module sends "RING" periodically on hyper terminal. Now, when i send some command to this module from hyper terminal instead of sending reply it sends same data back to me.
For eg. I send "AT+CMGL" it suppose to reply me with list of messages, but it sends me "AT+CMGL" back.
Similarly, if i send any data it send same data back to me.
I have checked for continuity between Rx and Tx pins of module, but there is no continuity between them ie they are isolated.
I am struggling from last two days with no success. Basically i want to read the incoming message.
Are there some first time settings required ?
Or my module have some problem ?
If anyone knows please help,
Thanx.

 

[sribangaram]

USB to Serial converter purchased or you make I think problem is in converter side

 

[ashokb]

USB to Serial converter purchased or you make I think problem is in converter side

I purchased that converter few months back, and that work's fine for other applications. Even i tried on "COM1" ie my desktops default com port and i get same results there as well.

 

[xpress_embedo]

Type AT Command see if it is returning OK or not.

I am thinking its echo effect.

type this command

ATE0
and then save setting in EEPROM
AT&W
Hope it will work

 

[peeyushsigma]

Check whether you are adding " CR(carriage return)+ LF(Line Feed) " at the end of Every Command.

 

[ashokb]

@xpress_embedo
@peeyushsigma
Hey Hi... Thanks for help and sorry for late.
Just before few minutes I tried the options suggested by both of you and now my modem is responding me as expected. I can read messages now.
Previously I am not using carriage return at the end of command. Also i got first time response when i send ATE0 command. The response was some error (which i forgot), but still that made me happy because there is response from modem, then i send AT&W and response was "OK", and now am enjoying and playing with other commands.
I am really very thankful to both of you. Hartley Thank you to both of you. You really made one person happy today by helping.
Keep helping.