IoT Energy Meter with Live Consumption Dashboard

Energy monitoring is one of the most genuinely useful IoT builds: it makes invisible consumption visible. This meter does it with real metrology instead of estimates. A PZEM-004T module — with its own current transformer and voltage sensing — measures true RMS voltage, current, active power, power factor and cumulative energy of a connected demo load; an ESP32 reads it over Modbus-RTU, publishes the data over Wi-Fi via MQTT, and a live dashboard renders the current draw, power trend graph, daily energy bars and a running cost estimate from a configurable tariff. A daily budget feature alerts when consumption crosses the set kWh, and an overload threshold flags abnormal draw. The listing is careful about scope: this monitors a single demo load circuit (it is not a replacement for the utility meter), and CT orientation and burden behavior are documented so the viva covers real metering concepts.

1. The PZEM-004T's clamp CT and voltage terminals measure the demo load circuit; its internal DSP computes RMS voltage, current, active power, power factor and cumulative energy.
2. The ESP32 polls the module over Modbus-RTU (TTL serial) on a fixed interval and validates each frame's checksum.
3. Readings are published as JSON over Wi-Fi via MQTT to the cloud backend, which stores the time series.
4. The dashboard renders live power, the power trend graph, daily energy bars, cumulative totals and the tariff-based cost estimate.
5. When daily consumption crosses the configured budget — or instantaneous power crosses the overload threshold — a push alert is sent.
6. The CT orientation and zero-offset notes in the setup guide keep the measurements honest; the report's data section is built from the buyer's own logged readings.

Tech stack:

• ESP32 development board
• PZEM-004T energy metering module + clamp CT
• Modbus-RTU over TTL serial
• MQTT broker + cloud dashboard (web)
• Configurable tariff engine (dashboard-side)
• Mobile push alert service
• Arduino IDE (C/C++ firmware)

• [True electrical metrology] PZEM-004T with clamp CT measures RMS voltage, current, active power, power factor and cumulative energy — real metering, not estimates.
• [Live consumption dashboard] Current power draw, power trend graph, daily energy bars and cumulative totals on a working dashboard alongside the hardware.
• [Tariff cost estimate] A configurable per-kWh tariff converts energy into a running cost estimate — the number that makes consumption tangible.
• [Daily budget alerts] A configurable daily kWh budget triggers a push alert when crossed, with the dashboard showing progress against it.
• [Overload flagging] A configurable power threshold flags abnormal draw (e.g. a forgotten heater) on the dashboard and via alert.
• [Modbus-RTU interfacing] The ESP32 talks to the PZEM-004T over Modbus-RTU — genuine industrial-protocol experience for the report.
• [Load-profile logging] Timestamped readings are stored for daily/weekly comparison, so the report's data section shows real consumption patterns.

• Working energy-meter prototype (ESP32, PZEM-004T with clamp CT, demo load)
• Complete firmware source code (Modbus polling, checksum validation, MQTT telemetry, alert logic)
• Cloud pipeline + working dashboard (live power, graphs, cost estimate, alerts) demonstrated with the prototype
• Circuit and wiring documentation with CT orientation and AC safety notes
• Component list with ratings
• Tariff configuration and buyer-run verification procedure (compare against a plug meter)
• Project report PDF (energy metering background, Modbus/power-factor theory, methodology, test procedure)
• PPT presentation for final review
• Viva Q&A preparation document (true vs apparent power, CT behavior, Modbus framing)
• Setup and demonstration guide

• This monitors a single demo load circuit; it is not a replacement for, or wired into, the building's utility meter or distribution board.
• Metering accuracy follows the PZEM-004T module's datasheet; the verification procedure compares it against a plug-in power meter during the buyer's own check — no certified-meter claims.
• Cost estimates depend on the buyer-entered tariff; time-of-day tariffs are a possible extension, not in the base build.
• Push alerts need internet on the node and the phone; outages queue nothing.
• CT must be clamped with correct orientation and on the live conductor only — documented in the safety notes.