In order to test low-cost monitoring system in the field, one pond of the Burnley campus of the University of Melbourne has been equipped with a reference sensor.
The sensor used is a brand new PLS sensor from OTT. The sensor measure water depth and can communicate using SDI-12 communication protocol. The sensor is expected to have an accuracy of 1 mm and has proven its reliability over many years of field monitoring. The probe provide also the water temperature.
The Data logger is a MKR 1300 LoRa board coded in C++ using the Arduino IDE. Every five minutes the water depth and temperature is measure, an offset (constant) is applied to the water depth in order to obtain the water level.
The OLED screen always display the last measure values and allows to easily check on the gauge that the value is correct.
Both water level and temperature are sent through LoRaWAN to a google spreadsheet.
The data is then in real-time send from the google spreadsheet to the Mind4Stormwater online platform. Before sending the data, the google spreadsheet fetch the cumulated rainfall (since 9am) from the closest BOM (Bureau of Meteorology) station.
The code is accessible on Github: https://github.com/fcherqui/Mind4stormwater/tree/master/Burnley_pond Using a MKR 1300 LoRaWAN board