ESPHome IoT Firmware Framework

ESPHome is a system for creating custom smart home devices using ESP8266, ESP32, RP2040, and other microcontrollers, with configuration written in simple YAML files instead of programming. Created by Otto Winter in 2018 and now part of the Nabu Casa team, ESPHome integrates seamlessly with Home Assistant. Key features: YAML-based configuration for sensors, actuators, and components without writing C code. Native Home Assistant integration via native API for direct device-to-hub communication without MQTT overhead. Supports over 300 hardware components including temperature sensors (DHT22, BME280, SHT3x), relays, LEDs (WS2812, APA102), displays (OLED, e-ink, LCD), RFID readers, GPS, and environmental sensors. OTA (Over-The-Air) firmware updates via WiFi for remote device management without physical connection. MQTT client support for non-Home Assistant integrations. Bluetooth Low Energy BLE client and proxy for relaying BLE sensor data. WiFi and access point configuration via captive portal for easy onboarding. Deep sleep mode for battery-powered devices with configurable wake intervals. Custom C++ components for advanced users needing full programmatic control. I2C, SPI, UART, and GPIO interfaces for connecting peripherals. Dashboard web interface for managing multiple devices from one location. Conditional compilation and substitution templates for reusable configurations. Time, sunlight, and automation logic built-in.