IoT-Based Home Care System with a FPGA Development Board by Using RS-485 Interface and Verilog HDL

This paper presents the packet processing and transmission of a field programmable gate array (FPGA) development board by using an RS-485 interface module and Verilog HDL. The proposed communication protocol was established between the sensors in the sensing layer and web server. In the sensing layer, the sensor system, which comprises a temperature sensor, warning light, and fan, controls the environment temperature. An attractive Internet of Things application system was proposed to simultaneously monitor real-time temperature information through wireless communication and the webpage. Node-RED software was used to develop the home care system because of its advantages in facilitating management and maintenance. The linkage function was written in the JavaScript language on Node-RED software. In the designed system, when the temperature reaches the preset value, the fan and warning light automatically turn on and a notification email is sent to the user. The measurement results showed that the throughput and conversion time were 0.00958 Mbps and 283.83 ms, respectively, at a clock frequency of 1 MHz and Baud rate of 9600 bps.