SmartStrip — Intelligent 5-Socket Energy Monitoring Extension

SmartStrip — Intelligent 5-Socket Energy Monitoring Extension SmartStrip transforms a standard 5-socket extension box into a smart, self-hosted energy monitoring and control system — built from the ground up at RAIN (Robotics and Artificial Intelligence Nigeria) in Ibadan, Nigeria. ## The Problem Most Nigerian homes and offices have no visibility into how much electricity individual appliances consume. With unstable power supply, prepaid meters, and rising NERC/DISCO tariffs, energy waste is expensive and invisible. SmartStrip solves this by giving users per-socket insight and control — without relying on expensive imported smart home ecosystems that aren't built for the Nigerian context. ## What It Does SmartStrip monitors and controls 5 independent sockets in real time: - **Per-socket energy monitoring** — voltage, current, active power, energy (kWh), power factor, and frequency are measured independently for each socket using dedicated PZEM-004T V4.0 sensors - **Remote relay control** — each socket can be switched ON or OFF remotely via MQTT from the web dashboard - **Electricity cost calculation** — uses PZEM's built-in kWh accumulator multiplied by a user-configurable tariff rate, reflecting real Nigerian electricity billing - **Real-time dashboard** — a six-page HTML/JS web interface displays live readings, analytics, schedules, and settings - **JWT authentication** — secure login system protects access to the dashboard and API - **Schedule automation** — sockets can be programmed to turn ON or OFF at set times automatically - **Self-hosted architecture** — no cloud dependency, no subscription fees, runs entirely on local infrastructure ## Hardware Stack | Component | Role | |-----------|------| | ESP32-WROOM-32 | Main microcontroller, WiFi, MQTT | | 5x PZEM-004T V4.0 (100A) | Per-socket energy measurement | | 8-channel 12V relay module | Per-socket switching | | HLK-PM03 PSU | Mains to DC power conversion | | CT clamps (x5) | Non-invasive current sensing | | Sony 12V 3A adapter | Relay coil power supply | ## Software Stack | Layer | Technology | |-------|------------| | Firmware | Arduino C++, PubSubClient, HardwareSerial | | Backend | FastAPI, SQLAlchemy 2.x, SQLite | | Auth | JWT via python-jose, passlib, bcrypt | | Broker | MQTT via HiveMQ | | Frontend | HTML, CSS, JavaScript (6 pages) | | Protocol | MQTT pub/sub for real-time data | ## How It Works The ESP32 polls all 5 PZEM sensors every 2 seconds using two hardware UART buses — PZEM1 on UART1 and PZEM2-5 sharing UART2 via unique Modbus addresses (0x01–0x05). Readings are packaged as JSON and published to MQTT topics per socket. The FastAPI backend subscribes to these topics, logs data to SQLite, and serves the web dashboard. Users can toggle sockets from the dashboard, triggering MQTT control messages that the ESP32 receives and acts on by driving the relay IN pins LOW. ## Nigerian Market Context SmartStrip was designed with the Nigerian electricity landscape in mind: - **220V mains** wiring throughout, following UK conventions (brown/blue/green-yellow) - **Service Based Tariff** support for accurate cost calculation - **Prepaid meter awareness** — helping users track consumption before their units run out - **Local sourcing** — all components sourced in Ibadan - **Self-hosted** — no dependence on foreign cloud infrastructure ## Build Journey SmartStrip was built entirely from scratch as an internship project at RAIN from initial ideation and component sourcing, through full physical assembly (drilling, wiring, casing), to firmware development and web application. The build involved real engineering challenges including UART bus sharing for 5 sensors, GPIO pin conflict resolution, mains wiring debugging, relay power supply design, and full-stack API development with authentication. ## Built at **RAIN — Robotics and Artificial Intelligence Nigeria** Ibadan, Nigeria · 2026