Need GSM module, but don't know which to choose (For PIC MCU)

Thread Starter


Joined Mar 18, 2010
I am working on security system project. I am need of GSM Module to connect to my PIC MCU. I haven't use any GSM modem yet so before ordering any model, i need some advice.

I have heard of SIM900/SIM900A/SIM900D & SIM900 mini. I don't know whats the difference in them & which one should i choose for my project ?

I just want GSM module to transfer SMS and call to number in some critical time, so i don't need any fancy modem to this, i just want a model to be of that specific.

I was just surfing in search of models and i kinda like the structure of SIM900 MINI .

P.S : Is there any Software simulator for AT-Command, so that i can work in virtual environment (not using physical modem) so that i can get my hands on AT-commands and its response.

Any advice will be appreciated.


Joined Dec 2, 2013
I used the sim900BE ( this includes simcard holder)
doing SMS ftp E-mail works perfect and is cheap.
At commands are simple. ( sms 5 AT strings approx)
My proto attached.
Using pic18F8722 gps one e-mail plus one SMS per day.
It is running 5 x AAA (2100mA/H) now for 13 months without recharge ( voltage now is 6.24V)
Current usage in sleep mode: 55microAmps approx.