About GSM Module The GSM module that we are going to use here is SIM800L. It is compact and highly efficient as compared to other GSM modules. This type of module is used when you want to work on a cellular network using an Arduino. The SIM800L supports quadband frequencies of 850/900/1800/1900MH. By using this module you can easily transmit voice, send SMS, and access the Internet. When you power up this module with a power supply of 3.8-4.2 Volts the LED present on the board will starts blinking. If it is blinking very fast that means SIM is not registered to any network. If it is blinking slowly then SIM has successfully logged in to the network. Make sure your power supply is of at least 2A as this module consumes lots of power. Pin diagram of the SIM800L Features of the SIM800L Input voltage: 3.8-4.2V Operating current: 2A…