MESH - A Low-Cost Solution for High Spatial Density Sensor Networks

With the increased usage and reliability of low-cost sensors for atmospheric observations, the ability to implement high density sensor networks has become much more feasible. One hurdle that needs to be considered when developing a high density network is how the individual stations will upload data to the cloud if they are not just logging data locally to a SD card. Installing a low-cost cellular modem at each station is a viable option for data upload, but this adds close to $100 per station to implement. This presentation will demonstrate an alternative method using LoRa (Long Range) Radio to create a mesh network between the stations with a single station containing a cellular modem to upload the entire network's data to the cloud. To show a real-world example of this in use, we have created the Meteorological and Environmental Sensor Hub, which includes 20 stations measuring a few state variables, namely temperature, pressure, and relative humidity. Each station operates from a LoRa32u4 ii development board which utilizes an ATmega32u4 as the central microprocessor and a HPD13 915 MHz LoRa Radio module as the transceiver. The central station of the network additionally includes a Sparkfun LTE CAT M1/NB-IoT Shield - Sara R4 cellular modem that is used to upload the entire network's data to the cloud. We will discuss the advantages and limitations of the network, as well as potential applications for such a network.