ESPHome Custom Climate Sensor
Building a custom ESPHome component for a climate sensor that integrates seamlessly with Home Assistant. Custom C++ component with auto-discovery.
Why Custom Components?
ESPHome has great built-in support for common sensors, but sometimes you need custom behavior — like combining multiple sensors into a single climate entity, or implementing a custom calibration algorithm.
Component Structure
ESPHome custom components are C++ classes that inherit from Component and optionally Sensor, BinarySensor, or Climate. The framework handles WiFi, MQTT/API, and OTA updates.
Implementation
This component reads from a BME280 and a PMS5003 particulate sensor, calculates an air quality index, and exposes it as a Home Assistant climate entity with temperature, humidity, and AQI attributes.
Home Assistant Integration
ESPHome's native API provides auto-discovery in Home Assistant. Once the component is deployed, it appears automatically with all its sensors and controls.