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Kellen Butler
Experiment

Water Softener Monitor

A practical little build that solves a genuinely annoying problem: you never know your water softener is low on salt until something’s already off. This watches it for you and quietly reports in.

Hardware & home automation

What it is

A small sensing project: an ESP32 paired with an ultrasonic sensor measures the salt level in a water softener and broadcasts the reading over Wi-Fi to Home Assistant, where it becomes a value you can see and alert on.

Why I built it

It scratches a very ordinary itch. A water softener quietly runs out of salt, and you usually find out the hard way. Rather than remember to check it, I wanted the system to tell me — turning an invisible household state into something visible and actionable.

How it works

The ultrasonic sensor measures the distance to the top of the salt, the ESP32 turns that into a level reading, and the device reports over Wi-Fi into Home Assistant. From there it’s just data — easy to chart, easy to alert on, easy to build on.

What it points toward

On its own it’s a small, practical build. But it sits squarely in a space I keep returning to: quiet monitoring of real-world systems, turned into useful visibility and timely alerts. It’s a sketch of a larger product idea — practical software meeting the physical world — kept honest by actually running in a real home.