Problem of sim900 module gprs

[aleynasarcanli]

I made everything, led is blinking its true, but when I send "AT" nothing response, What is the default baud rate of simcom sim900 ? strange response when start with powerkey.. for example "IIIIÿþÿþ"

 

[hobbyckts]

Default baud rate will be 9600..

How you have done your interface?

The response which you are getting is some kind of junk...

 

[aleynasarcanli]

Breadboard connections below. 3.6 v 3A powered breadboard.

 

[hobbyckts]

Expected some schematic from you... But your picture gives a fair idea about it.

So the interface between the GSM and the PC is through FT232 (UART-USB)?

Power supply Range which you range? (both voltage and current required)

I couldn't able to locate the SIM card slot in your picture.

What are all the signals which you have chosen from GSM.

 

[FvM]

Default baud rate will be 9600..

Default setting is AT+IPR=0 (autobaud). Default baudrate is nevertheless 115200, read the SIM900 AT manual.

It's also said that module is sending a few bytes at 115200 during startup.