The SIM800L is a GSM module from Simcom that gives any microcontroller GSM functionality, meaning it can connect to the mobile network to receive calls and send and receive text messages, and also connect to the inter
GSM modules use a SIM card and an RF chip to connect to the internet and phone network, providing microcontrollers with the capability to make calls and send SMS messages.
The SIM900A is a readily available GSM/GPRS module,used in many mobile phones and PDA. The module can also be used for developing IOT (Internet of Things) and Embedded Applications.