GSM SIM card interfacing with microcontroller

[nyl]

Thanks for the quick reply!
would like to clarify with you regarding the power supply. in the g24-l datasheet it says that max input to pin is 3.0V, while my power supply to PIC is 5V, effectively will output from pic be approx 5V too - and damage the gsm?

 

[xainnasir]

Thanks for the quick reply!
would like to clarify with you regarding the power supply. in the g24-l datasheet it says that max input to pin is 3.0V, while my power supply to PIC is 5V, effectively will output from pic be approx 5V too - and damage the gsm?

power supply wont create any problem ...... give 5V to pic n 3.3 to gsm ..... it will work perfectly ...

 

[nyl]

power supply wont create any problem ...... give 5V to pic n 3.3 to gsm ..... it will work perfectly ...

Sorry for the late reply, I have been busy with work. I tried, but it didn't work. Right now i'm trying to test it using Hyperterminal via a USB/Serial cable. I am expecting a reponse of "OK" when i input "AT". However this is not occurring as well. I realised that it might be because i did not switch it on properly (i.e. configuring IGN, CTS_N and RESET_N). I've done this according to the timing diagram in the operating instructions using the PIC18f4520.

Another doubt I have is my connection to the G24L via serial cable. Currently I am connecting TX(serial cable) --- R2IN (MAX3232) --- R2OUT (MAX3232) --- RX (G24L)
and RX - T2OUT - T2IN - TX. Is this right? Based on the G24L datasheet, it is saying that data flow btwn DTE (UART) to DCE (G24L) is TXD --- TX, RXD --- RX etc.

Please help! Thanks!