PROJECT 03 · ENERGY METERING
15-channel energy meter — three phases, fifteen circuits, one board
Sub-metering for distribution boards: one board measures three phase voltages and fifteen circuits at the same instant, keeps the measurement galvanically isolated from the network side and reports over Ethernet or Wi-Fi.
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18synchronous channels: 3 voltages + 15 currents
6400samples per second on every channel, all at once
2processors: PIC32MZ measures, ESP32 communicates
1isolation barrier between the mains side and the network
Three 24-bit metering ADCs on one shared clock — voltage and current are sampled at exactly the same instant, so power is computed from truly simultaneous values.
Per circuit: RMS current, active power, imported and exported energy. Per phase: RMS voltage and frequency.
Real-time DSP on a PIC32MZ: filtering and RMS integration in the sampling interrupt, hand-optimised where every microsecond counts.
Energy counters in FRAM, saved periodically and on demand — they survive power cuts. Automatic phase calibration.
Current transformers up to 120 A on pluggable terminals, three-phase + neutral voltage input, separate low-voltage supply.
Network side on ESP32: Modbus TCP (several clients), MQTT with JSON, built-in web interface, over-the-air updates — Ethernet or Wi-Fi.