Hi guys, just a general question. Currently studying a electronic board with a GSM module. The GSM module they use is Wavecom Wismo Q2403B. It is interfaced with PIC18F8722 mcu and I want to send a few AT commands from the mcu to see if the GSM module is working.
May I ask, do we have to put in the SIM card only it will reply? I mean command without involving SMS, like manufacturer identification AT+CGMI, model identification AT+CGMM or the Product Serial Number AT+CGSN.

 

I already tried it without using SIM card. Seems like it doesn't reply anything when I use those command. So, is it we must use SIM card?

 

got a datasheet/link?

 

got a datasheet/link?

I've uploaded the datasheet for your review.

 

if, like i suspect, the uart is being used, id check the baud rate of the processor, if you can connect it to a pc and send it a 0x55 command, then view the baud rate registers (using auto baud mode) i reckon itll be something different to what is calculated... have you used the uart with other devices?