Design and Implementation of Cloud-based Single-channel LoRa IIoT Gateway Using Raspberry Pi

摘要

With the emergence of industry 4.0 and Internet of things (IOT), more and more practical requirements need seamless connection from the smallest sensor to enterprise level systems and other systems with simple, convenient, reliable and economic approach. LoRa is a low-power wide area network (LPWAN) solution specifically designed for IoT devices that send and receive small amounts of data over a range of many kilometers with minimal power consumption. At the system architecture level, Lora is considered as a physical layer technology based on OSI model, mainly based on Chirp spread-spectrum(CSS) technology. LoRa is resulted in a robust and reliable technology compared to other standardized wireless solutions such as Zigbee, Bluetooth, WiFi, and 3G/4G cellular. In this paper, we have designed a single-channel LoRa gateway for Industrial IoT cloud applications using inexpensive single-board computer naming Raspberry Pi plus a LoRa add-on board with the necessary integrated circuits for wireless data communication. The system adopting the LoRa LPWAN technology consists of end devices, gateways, and cloud IoT services. The proposal gateway sends and receives LoRa messages to and from end devices and communicates with upstream cloud application servers through HTTP RESTful protocol and IoT-standard MQTT protocol, according to different data types and specific functional requirements. Unlike other ready-to-use LoRa gateways available on the market in which these gateways simply pass all the original LoRa packets back and forth between and network server over the air called "packet forwarding" mode, the proposal gateway contains smart-agent managing connectivity to devices, coordinating polling mechanism, decoding the packets, passing periodically the unified data to the public or private cloud service applications. Aside based on the embedded web server, the configuration of the gateway is carried out through the web page with desktop or mobile application and it can be updated anytime & anywhere when necessary. The proposal gateway is built cloud ready and can easily integrate with existing networks and enables low-cost, long range communication capability for a multitude of industry applications with minimum effort.