GSM modules are fascinating to use especially when our project requires remote access. These modules could make all actions that our normal mobile phone could do, like making/receiving a call, sending/receiving a SMS, connecting to internet using GPRS etc. You can also connect a normal microphone and speaker to this module and converse on your mobile calls. This will open doors to lot of creative projects if it could be interfaced with a Microcontroller. Hence in this tutorial we will learn how we can Interface the GSM module (SIM900A) with our PIC microcontroller and will demonstrate it by making and receiving call using GSM Module. We have previously interfaced it with Arduino and Raspberry Pi for calling and messaging
We have simply interfaced the Tx and Rx pins of the GSM module with the Rx and Tx pins of the PIC MCU PIC16F877A respectively. This will establish a Serial connection between both. Also, so do not forget to common ground both the GSM and PIC module. We have also used a LCD display to know the status of our GSM module. Once the connections are done your hardware will look like something below.