I'm developing an open-source water meter for Home Assistant and thought the HN community might be interested. I've been using some version of it after a few costly toilet leaks that my city meter missed. Recently, I decided to polish it up so others could use it. It might also function as a gas meter reader (https://youtu.be/9Dso4EBAoiE), but this is still experimental.

The device runs on 3 AA batteries and utilizes an ESP32-S3. It works by measuring the spinning magnet inside the brass housing. It stays in deep sleep until it needs to transmit usage or leak information. It's not an ideal CPU for battery-powered devices, but I chose it because it has a lot of support in the home automation community. To compensate for the power-hungry CPU, I am handling rotation counting and leak detection in programmable hardware. Currently, it consumes 50-75uA while the ESP32 is sleeping. The programmable hardware makes it an interesting platform for other use cases like electricity meter monitoring.

I'm planning on selling the hardware and potentially offering a hosted solution for those who don't want to set up Home Assistant if there is demand.

There is still a lot to do, like designing a waterproof case and completing the software. If you're interested in the details, I have a project log on Hackaday. Feedback, feature requests, and contributors are always welcome.

Website: https://y-drip.com

Github: https://github.com/YDrip

Short demo: https://youtu.be/7eXRLN7OWA0