Fast UART and SPI Protocol for Scalable IoT Platform

Abstract

This paper proposes the enhancement of Universal Asynchronous Transmitter Receiver (UART) and Serial Peripheral Interface (SPI) protocols for improving the node performance in the Internet of Things (IoT) platform. Implementation of UART communication protocol on IoT in microcontroller ATmega328 has limitation of Serial Hardware scalability so it must do bit banging which can affect performance and lack of speed. SPI requires change of SPI Control Register (SPICR) to become Slave Select which can affect speed and also have limited of Slave Select. There are many previous methods that have been proposed to solve this problem. However, none of them are scalable and speed aware. This proposed method uses parallelism concepts by implementing hardware environment. Through some experiments, this research succeeded to implement UART on FPGA where the speed is 67,3% faster than the microcontroller ATmega328 and is able to reach four UARTs. SPI Slave on FPGA has speed up to 73.43% faster than the microcontroller ATmega328 and is able to expand to two SPI Slaves.