GSM GPRSW Modem

Here we are with yet another post on our favorite Pi. We had many different posts on Raspberry Pi as well as on GSM-GPRS connectivity. So what do we have here new? What we discussed so far focused either on GSM connectivity or TCPIP connection over GPRS, here we intend to tether our Raspberry Pi to the internet through a GPRS cellular data connection. Lets see how its done. Make the connections as shown in the figure above. Provide separate power source (5V 1A) to the GSM modem for proper functioning as it drives much current. Insert a 2G activated SIM card, with working data connection, and power up the modules. It will take a few seconds for the SIM to get registered to the network. Now we need to check the communication between the RPi and the modem. For which, we make use of a python code that transmits an AT command and verifies whether an OK is received as acknowledgement. Open a python shell using sudo idle command and create a new file. Copy the code shown below, save and run the code.