Open Source • Local • ESPHome

DIY Water & Energy Meter for Home Assistant
— 100% Local & Cloud-Free

Convert any pulse-based water or energy meter into a smart Home Assistant sensor. Monitor usage in real-time, automate energy savings, and keep all your data private.

What is S0tool?

S0tool is an open-source solution that transforms any pulse-based water or energy meter into a smart sensor for Home Assistant. Fully local and cloud-free, S0tool gives you instant insight into your consumption without relying on third-party services.

How It Works

S0tool reads pulses from your meter and converts them into data your Home Assistant can understand. Works with water meters, electricity meters (kWh), and other pulse-output devices. Data updates in real-time, enabling instant automation and energy monitoring.

Why Choose S0tool?

Real-Time Monitoring

Track water and energy consumption instantly — no delays, no cloud.

Smart Home Integration

Seamlessly integrates with Home Assistant and ESPHome for automation and dashboards.

Energy Optimization

Feed data directly into Home Assistant’s Energy Dashboard to optimize usage.

100% Local & Private

No cloud, no subscriptions — your data stays secure on your network.

By the Numbers

20+
Compatible Meters
100%
ESPHome Ready
100%
Home Assistant Ready
100%
Local
100%
Open Source
24/7
Monitoring

Compatibility

Brand Model Type Status Region
Elster V200 💧 Water Compatible NL
Itron Aquadis+ 💧 Water Compatible NL
Sensus 620 💧 Water Compatible NL
Maddalena CD SD Plus 💧 Water Compatible BE
Actaris Single-Jet 💧 Water Compatible NL
Zenner MNK-RP-N 💧 Water Compatible DE
Kamstrup Multical 21 💧 Water Compatible EU
Diehl Hydrus 💧 Water Compatible EU
Eastron SDM120 / SDM220 ⚡ kWh Compatible EU
ABB B23 / B24 series ⚡ kWh Compatible EU
Schneider iEM3000 series ⚡ kWh Compatible EU
Carlo Gavazzi EM24 / EM340 ⚡ kWh Compatible EU
Finder 7E.23 / 7E.36 ⚡ kWh Compatible EU
Eltako DSZ15D-3x80A ⚡ kWh Compatible EU

Your meter not listed? Add it via Community →

Brand Model Type Status Region Notes
Elster V200 💧 Water Compatible NL
Itron Aquadis+ 💧 Water Compatible NL
Sensus 620 💧 Water Compatible NL
Maddalena CD SD Plus 💧 Water Compatible BE
Actaris Single-Jet 💧 Water Compatible NL
Zenner MNK-RP-N 💧 Water Compatible DE
Kamstrup Multical 21 💧 Water Compatible EU
Diehl Hydrus 💧 Water Compatible EU

Your meter not listed? Add it via Community →

Brand Model Type Status Region Notes
Eastron SDM120 / SDM220 ⚡ kWh Compatible EU S0 pulse terminals
ABB B23 / B24 series ⚡ kWh Compatible EU External S0 wiring required
Schneider iEM3000 series ⚡ kWh Compatible EU Needs S0 connection setup
Carlo Gavazzi EM24 / EM340 ⚡ kWh Compatible EU Pulse settings configurable
Finder 7E.23 / 7E.36 ⚡ kWh Compatible EU DIN rail mountable
Eltako DSZ15D-3x80A ⚡ kWh Compatible EU DIN rail mountable

Your meter not listed? Add it via Community →

Made for ESPHome

Official Made for ESPHome

S0tool carries an official Made for ESPHome license — ensuring seamless integration and reliability.

Get in Touch

Questions, bugs, or ideas? Connect with us:

Email Us Discord (NL/EN) Community