The meter comes with an electronic control box, but we found that integrating directly with the sensor was simple enough and saved us some additional wiring and space. As water passes through the flow meter, an impeller rotates and toggles an output line which can be used to calculate the amount of water used. In addition to measuring the quantity, we also included a thermister (thermally-controlled resistor) to sense temperature.

Since we wanted to have an internet connected data-stream of our water usage, we decided to try out the YellowJacket Arduino with built-in WiFi. Data was then sent to the server at regular intervals when the water source was in use (from 1-15 seconds depending on the wireless setup and resolution desired). Using a GET request with ID and usage information, the server was then able to store and retrieve sensor data. The complete circuitry and code (see download link below) were both conceptually straight-forward and easy to implement.

Over a quick 2-hour build session with the team, we created 4 working units. Each consisted of the WiFi Arduino, temperature sensor (shown on the right connected to the yellow wire), the flow meter, and two fitting adapters (for use in the shower). We also hooked one up to our kitchen faucet, which ended up providing the most interesting data due to its frequent usage throughout the day.

To visualize the data and make sense of water usage patterns over time, we also put together a simple HTML5 graphing tool, called Flow. Using a modular design, we were able to dynamically layout the content to fit screens of all sizes, from iPhone and iPads to laptops and projectors. This allowed us to place a small display next to the faucet for immediate feedback, while still offering us a more holistic view to compare multiple sources and look at first-order trends.

And finally, to try it out yourself, here’s a ZIP file with the Arduino project, Eagle circuit schematic, and PHP/HTML5 code. The files are tuned for our quick prototype setup, but should also be helpful if you’re just getting started with hooking up a flow meter or Arduino WiFi data connectivity.