You can connect to a PC and the easiest way is to get yourself a USB - TTL converter, the 3.3V types and a Gadgeteer socket breakout board. If you use a USB - RS232 converter you will need a level converter in between. The first option avoids that and it’s a handy tool to have around to connect to Gagdgeteer UARTS anyway for testing
You’ll most likely need and external 5V power supply for it as the SIM900 is not designed for the limited 500mA current from the USB.
You can then connect it up and talk AT commands to it.
DOes anyone see anything wrong with this? For some reason i’m able to connect but the response is ‘CLOSED’…very unfriendly sounding and not what I expect.