The Elektor ESP32 Energy Meter is a device designed for real-time energy monitoring and smart home integration. Powered by the ESP32-S3 microcontroller, it offers robust performance with modular and scalable features. The device uses a 110/230 VAC to 12 VAC step-down transformer for voltage sampling, ensuring galvanic isolation and safety. Its compact PCB layout includes screw-type terminal blocks for secure connections, a Qwiic connector for additional sensors, and a programming header for direct ESP32-S3 configuration. The energy meter is compatible with single-phase and three-phase systems, making it adaptable for various applications. The energy meter is simple to set up and integrates with Home Assistant, offering real-time monitoring, historical analytics, and automation capabilities. It provides accurate measurements of voltage, current, and power, making it a valuable tool for energy management in homes and businesses. Features Comprehensive Energy Monitoring: Get detailed insights into your energy usage for smarter management and cost savings. Customizable Software: Tailor functionality to your needs by programming and integrating custom sensors. Smart Home Ready: Compatible with ESPHome, Home Assistant, and MQTT for full Smart Home integration. Safe & Flexible Design: Operates with a 110/230 VAC to 12 VAC step-down transformer and features a pre-assembled SMD board. Quick Start: Includes one Current Transformer (CT) sensor and access to free setup resources. Specifications Microcontroller ESP32-S3-WROOM-1-N8R2 Energy Metering IC ATM90E32AS Status Indicators 4x LEDs for power consumption indication2x Programmable LEDs for custom status notifications User Input 2x Push buttons for user control Display Output I²C OLED display for real-time power consumption visualization Input Voltage 12~16 VAC (via a step-down transformer 110/230 VAC to 12 VAC) Clamp Current Sensor YHDC SCT013-000 (100 A/50 mA) included Smart Home Integration ESPHome, Home Assistant, and MQTT for seamless connectivity Connectivity Header for programming, Qwiic for sensor expansion Applications Supports single-phase and three-phase energy monitoring systems Dimensions 79.5 x 79.5 mm Included 1x Partly assembled board (SMDs are pre-mounted) 2x Screw terminal block connectors (not mounted) 1x YHDC SCT013-000 current transformer Required Power transformer not included Downloads Datasheet (ESP32-S3-WROOM-1) Datasheet (ATM90E32AS) Datasheet (SCT013-000) Frequently Asked Questions (FAQ) From Prototype to Finished Product What started as an innovative project to create a reliable and user-friendly energy meter using the ESP32-S3 microcontroller has evolved into a robust product. Initially developed as an open-source project, the ESP32 Energy Meter aimed to provide precise energy monitoring, smart home integration and more. Through meticulous hardware and firmware development, the energy meter now stands as a compact, versatile solution for energy management.