Design of Compact LoRa Devices for Smart Building Applications.

The use of smart devices in buildings is many times compromised by its form and size. Smart devices are composed of several components including sensors, boards, batteries, processing units, and antennas. However, the form and size of the smart devices are usually limited due to antenna restrictions. In this paper, we propose the architecture of a compact low-cost LoRa smart device designed for easy deployment in smart building applications. The proposed device architecture features a reduced size embedded antenna and an ultra-low-power microcontroller to interface several sensors and actuators. The results obtained have shown that the proposed design can be used for communication, between two compact LoRa devices, in line-of-sight for up to 4.2 km, in urban environments for up to 1.2 km and also for in-building communications for up to 152 m, without compromising the low-power features that LoRa supports.