Análise da comunicação por Bluetooth Low Energy com pilha IPv6 usando os sistemas operacionais Zephyr e Contiki

Abstract

With the recent popularization of the Bluetooth Low Energy (BLE), several devices, that previously did not have access to the Internet, will have. With this, one way of achieving robust and efficient communication is of extreme importance. Therefore, for this work, we analyze two different real-time operating systems (RTOS) using the nRF52832 module, from Nordic Semiconductor, which has Bluetooth 4.2 communication hardware. Contiki OS and Zephyr OS are the RTOSs used, and both have their own IPv6 stack for BLE. In order to perform this work, the chosen protocol for the application layer is MQTT, because it is a light protocol and aimed for the world of IoT. It was evaluated the energy consumption during message publishing, and the maximum of data rate transfer, varying the size of the message and the distance between the devices. The project also includes all the necessary configurations for the proper functioning of the communication between a computer and the module with the RTOSs used. In this sense it has been shown that Zephyr OS has an average energy consumption of 5 to 10% lower than the Contiki OS, and data transfer rate between 3 to 4 times higher. However, Contiki appeared to have fewer communication failures than Zephyr during the tests performed, although it cannot be stated whether the failures observed in Zephyr were caused by software failures or external causes, such as interference.