3,500 litres of water, per person, per day. Yet we only drink 2 of these litres per day. To sustain our current way of life, this is the average quantity of water required to produce food, energy, equipment, etc. In the US alone, this average goes up to 7,000 litres. 80% of all diseases in the developing world are water related, according to the WHO.
A major portion of this water comes from waterways: protecting and monitoring theses ecosystems will be crucial to ensure the continuity of our species in the next decades.
Protecting waterways requires a twofold strategy: long and short term efficient monitoring. Monitoring waterways’ ecosystem in real time will provide us the means to analyse and better understand human impact, and to also act proactively if a brutal change is detected.
Watsyn, Water Analysis and Telemetry SYstem in Network, caters to the 4 cornerstones of IoT: Data collection, transmission, processing and energy management. It aims to give to mankind the means to monitor waterways, through a grid of inter-connected units gathering and analyzing water parameters such as temperature, pH, turbidity, conductivity, and water-flow.
The units also perform spectrophotometry analysis to track changes in the composition of water, and thus better detect contaminants.
With the small size of its units, Watsyn is designed to be deployable almost everywhere on earth, and to work autonomously: units produce, store, and manage their own energy, harnessing hydro and solar energy. Units are built using a great proportion of available components, and others can be 3D-printed (Shell, blades, etc.): costs are limited in order to make the project available to the greatest number.
Units send their GPS data and battery status, and measure with acceptable accuracy temperature, pH, TSS concentration (Total Suspended Solids, turbidity) and conductivity with probes currently available on the market or technically manufacturable. Water flow is also measured by measuring the current produced by the underwater turbine.
Watsyn offers an innovative solution with its ability to perform autonomously colorimetry and spectrophotometry.
A duct is opened and then closed using valves controlled by servo-motors. Once closed to insure obscurity, an RGB LED produces different wavelengths and a photocell measures the intensity received and thus the related absorbancy.
Watsyn units are connected in a mesh P2P network, using the LoRa technology. LoRa technology is used as it is energy-efficient and can be deployed on long-ranges (more than 10 kms), while allowing a sufficient bandwidth to transfer enough data over time (both in quantity and quality). LoRaWAN providers are deploying more and more Gateways around the globe, covering more and more areas Watsyn relies also on graph theory tools to optimize the network: Dijkstra and Ford algorithms, etc. It requires at least one unit connected to the other units to reach a LoRaWAN Gateway to provide a link between the mainland and the grid of Watsyn units. In term of graph theory, at least one vertices of each connected sub-graph needs to be connected to a Gateway. If no Gateways are reachable in the area, each one of theses vertices can be equipped with additional modules to reach the mainland through mobile networks.
The data transmitted inside and outside of the mesh LoRa network is compressed and integrity insured by checksum techniques, such as MD5.
Data is received either by Internet, or by a SMS-receiver. It then feeds a PostgreSQL and Elasticsearch Database, and process real-time analysis of the data using Apache Spark cores. This architecture enables real-time analysis on a massive data sets, and can be scaled on Cloud computing providers, such as AWS.
Watsyn units are designed to operate 24/7 in waterway for years. They power themselves using solar and water flow energy, through solar panels and an underwater turbine harvesting energy.
Relying on Arduino MCUs, which includes a sleep-mode, units can save a significant amount of energy. Below a critical level, units send their current GPS data, and go into deep-sleep, waiting for more energy to arrive.
Units consume at peak an average of 250mA (120mA to emit on LoRa network, 100mA to operate the servomotors, 40mA to receive GPS data, and 10mA for the sensors). Working at peak for 10 seconds each 10 minutes, it consumes an average of 4,2 mA.
With only a 2000mA battery, units can operate for 20 continuous days without any input of energy. With larger batteries, units can even operate for months or years, without any input of energy.
Analysis of the data provides means to track environmental changes, and to valuate human impact on waterways. It can also reveal localized and brutal changes of the ecosystem. A concrete case would be the event of an illegal-dumping: Should the authorities be alerted quickly, massive devastation could be prevented. Using the data, the population could also be warned of the degradation of water quality, and avoid illnesses of both humans and animals. It will also empower public water services to better process the resource, for instance to anticipate the inflow of degraded water quality.