problem with sim900A

[Ammy Rao]

hello
i m using a sim900A module with lcd and AT89s51
the data transmission between the mcu and sim900 is working but when i send "AT" it returns a 5X7 matrix as response
i dont know where the problem is
any at command i send it just return a 5X7 matrix as response on the lcd...
please anybody help me....i need to make it work urgent

 

[zia]

uae "AT\r" and it may be due to baud rate problem

 

[s.sudhakaran]

I have problem with sim 900a c+pin error can u help me how to clear the issues