EnergySnap

A battery-powered, portable open hardware energy logger that measures the consumption of a single-phase home system without touching the wires. It clips on with a current clamp, logs data to a microSD card from one day to several weeks, and downloads it via Bluetooth to a PC app. No cloud, no subscriptions, no invasive installation.

Schematics (KiCad), BOM and firmware are fully documented and open, so anyone can build it, study it and customize it.

A “snapshot” of your consumption, when and where you need it

EnergySnap was born for those who need real data, not estimates: leave it in the electrical panel for a few days or weeks, collect the data and analyse peaks, night-time consumption and hourly profiles. Compact, affordable and designed to be replicated — a complete maker project, from the schematic to the firmware up to the analysis app.

From the clamp to the chart, in 6 steps

Real battery life

Who is it for

Professionals — solar designers sizing systems and storage on real consumption data; electricians diagnosing anomalous loads by observing the system for days; objective reports to hand to the customer, before and after the intervention.

Hobbyists & makers — understand how much and when your home really consumes, room by room; hunt down the “energy hogs” and standby loads that weigh on your bill; the perfect base for energy-monitoring and DIY home-automation experiments.

Why does it last so long? Between samples the ESP32 goes into deep sleep, and the microSD and analog front-end are powered off (power gating). Data is always safe on the card, even with a dead battery.