[SOLVED] SIM 900 GSM module problem

[ddmukundan]

i have aproblem on interfacing GSM module with my dsPIC 30f4013.

when i send AT command the it is responding back with the same command i am not getting the response

i am sending like this

UART_TX[''A''];
UART_TX[''T''];
UART_TX[0X0D];

AFTER THAT I AM WAITING FOR RESPONSE

I AM GETTING

AT|| ON MY lcd

PLS ANY ONE KNOW THIS ISSUE PLS HELP ME

 

[DineshSL]

If your wiring is ok;
Can you try with 0x0A as terminating character instead of 0x0D ?
If didn't work try with both of characters at end.

 

[electronicsbasecom]

Hello,

Did you try to communicate with modem without uC, for example with PC. Did u check baudrate? For more shematic is needed.

 

[ddmukundan]

If your wiring is ok;
Can you try with 0x0A as terminating character instead of 0x0D ?
If didn't work try with both of characters at end.

i connected UART TX to modem RX

modem TX to UART RX

i tried with AT<CR><LR> also i tried AT<CR>

for all these 2 i am getting the echo back. i dont think that if wiring is not ok i wont even get echo back. am i right?

- - - Updated - - -

Hello,

Did you try to communicate with modem without uC, for example with PC. Did u check baudrate? For more shematic is needed.

yes i try to communicate with PC hyperterminal and mikroc UART terminal

in both i am getting the correct response.

only when i sending using uc i am not getting the response

i set the baud rate at 9600 .

when i am connecting the uc with pc i am able to transmitt and receive as well

 

[electronicsbasecom]

Than give us your schematic first rather than code.

 

[dubey]

hello,
i have the same problem, that i am getting Eco back my same command that i am sending to sim 900a.
i am using mega 16 uc. i have checked all my hardware connection several times they are all correct.
can any one have solution??