hello all,
first of all i am giving some brief of my project.
my project name is "gsm motor starter with authorization "
connection details as follows:
Arduino pin no. 2 ( i.e. Rx) ----> Sim900a ttl Tx
Arduino pin no. 3 ( i.e. Tx) ----> Sim900a ttl Rx
Arduino Ground ----> Sim900a ttl Ground
what i have done so far
my project application is by giving a miss call to gsm modem the arduino is collect receiving phone number and compare it with predefined number which i have already write in code. then as if it was first miss call the arduino energized one relay that is my motor start command. i have use relay NO contact for start the motor
after that when i will give second miss call to modem again arduino compare the number and energized other relay that is my motor stopped command. i have used relay NC contact for motor stopped command.
i am using arduino gsm.h library for this project
as for above description the project is working 
what i want to implement
my problem is that whenever i want to add predefined number for compare it with receiving number , every time i have to programmed arduino then it works fine but is there any way that i can save number in sim card and then read numbers from sim card and compare it with receiving number
by this my project has no dependency on me and anybody can save number in simcard and my project truly becomes independent..
i have done googling but didnt find fruitful results.
as i know that software serial library is conflict with gsm.h library so is there any way to implement AT commands with arduino gsm library ??? : :
following is one link that i supposed to do the work but it didnt 