[SOLVED] Sim908 netlight always on, cant receive response of any at command

[matxt]

Hello fellow, after several days searching google and reading the datasheet, I can not find the solution to my problem and I appeal to your kindness and intelligence. ;-)

I designed my own hardware, not achieving the sim908 reply me any AT command, I do not get OK, or RDY. I paired the DTE baudrate (ATmega2560) and modem communication port to 9600.

Netlight LED is always on and does not understand that I may be doing wrong,
Any help ???
:-(

Facts:
ATmega2560 MCU, hardware own development.
Power supply, the entire circuit 3A 4.6V.

 

[matxt]

solved
I was using transistors BC817 code 6C (40watt), both to excite pwrkey as netlight, I replace them with code 6B (25watt).

Netlight works and now I can receive commands after syncing the baud rate of the mcu and the module in 9600 with AT+IPR=9600.

regards.