I just configured and programmed the platform Arduino Mega2560 with Sim900 shield by declaring call.h library. I want to make a switch by phone call authorized. So I registered the phone number in the SIM at position 7 as long number (including country code +40xxxx as type 145) and started to test.
The big problem is that sometimes, not all the time, the software response positive (TRUE) even if I try to make a call from a different number. It seems that the function CallStatusWithAuth() does not work well, it should not return authorized for phone number not registered in the SIM.
What the problem with this function, why it works like that?