H2Flow
The H2Flow is a portable, affordable, universal water flow meter designed for homeowners to easily track their water usage. As water passes through the sensor on the back, a small turbine spins, which is detected by a built-in Hall Effect sensor. The sensor sends out small pulses that are fed into the device and processed by an Arduino Nano powered by a 9V battery.
The Arduino takes the raw water velocity data and converts it into liters, gallons, or ounces based on the user's selection using waterproof buttons. The device also features a "Maximum" mode, where the homeowner can set a maximum threshold of water usage using simple up/down controls.
The H2Flow is accurate to within 95.2% and can be used at any hose, shower, or spout in the home. Thanks to the compact design, portability and versatility are easy. Every bolt, screw, button, and switch is completely watertight, with a rust-proof aluminum casing, food-grade plastics, and a polycarbonate shield for impact resistance. With perfectly fit gaskets, the device blocks moisture while still allowing easy battery access. The device runs for up to 6 hours on a rechargeable 9V battery.
H2Flow was awarded both Section Winner and Best Design Overall for its functionality, durability, and user-focused design.
I designed and manufactured the polycarbonate shield for the H2Flow, integrating the waterproof user interface directly into it. I learned how to engrave text onto the shield using a laser cutter and wired the buttons into a custom-built perf board PCB that I designed. I also handled the full electrical system—selecting the right flow sensor, building out the perf board circuit to connect the sensor, LCD display, and control buttons, and making sure everything was watertight and compact. I programmed the Arduino Nano to process the raw pulse data from the Hall Effect sensor and output real-time water usage in the units selected by the user.
