MQTT based Wi-Fi communication between Microcontroller and FPGA

This paper explains the design, implementation, and application of communication between Microcontroller and FPGA using MQTT protocol. While there has been similar communication between the Microcontroller and FPGA using Bluetooth and RF modules, Wi-Fi modules can establish a larger network for communication, have larger coverage, and higher speed. Embedded systems using both the FPGA and microcontrollers bind the devices to performing specific functionalities, such cross-platform communication is not common. The use of microcontrollers in embedded systems is common because they are user friendly and comparatively easy to program. FPGA however involve parallel programming, increasing design complexity while increasing processing speed. FPGA can be used as central processing unit that improves system performance and frees up microcontrollers from cycle intensive tasks. In this project, the MSP432 microcontroller and BASYS3 FPGA board are made to communicate by using a MQTT protocol. A mobile application which acts as a MQTT. broker (server) is initialized at certain static IP address. The Wi-Fi module connected to the MSP432 generates an Access Point to which the Wi-Fi module at BASYS3 and the mobile phones connect to. This establishes a wireless network between the three devices. Messages are then exchanged using UART communication which sends or receives characters on pressing the onboard pushbuttons. Bidirectional messages are sent or received based on the publisher/subscriber mode of BASYS3 and MSP432 board.