A motion sensor that only turns lights on when it’s dark is one of the most useful smart home automations.By combining a PIR motion sensor with a simple LDR (light-dependent resistor) and an ESP32, it’s easy to build a local,…

The Sensirion SGP40 is one of the easiest ways to add VOC monitoring to Home Assistant with an ESP32 and ESPHome. It connects over I²C and ESPHome handles the important part automatically: converting the sensor’s raw signal into Sensirion’s VOC…

Combining a PIR motion sensor with an LDR light sensor is one of the most flexible ways to create intelligent room automation.With this setup, lights can automatically turn on only when the room is dark and motion is detected —…

Controlling a DC fan using PWM (Pulse Width Modulation) is an easy and cost-effective way to cool network cabinets, 3D printer enclosures, AV racks, routers, amplifiers, or any electronics that require temperature-activated airflow. This guide explains how to use an…

A reed switch is one of the simplest and most reliable ways to detect when a door or window opens. When combined with an ESP32, it becomes a fast, local, battery-free, and cloud-free door sensor that integrates perfectly with Home…

Monitoring indoor CO₂ levels is one of the most effective ways to track air quality, improve ventilation, and maintain a healthy indoor environment.The SCD30 and SCD41 are two of the best consumer-grade CO₂ sensors, offering accurate measurements and excellent long-term…

The ESP32 Bluetooth Proxy solves this problem by extending Home Assistant’s Bluetooth range using inexpensive ESP32 boards placed around the home. Bluetooth Low Energy (BLE) sensors such as the Xiaomi Mi Temperature, Inkbird, Switchbot, and many others are extremely popular…

Passive Infrared (PIR) motion sensors are one of the simplest and most effective ways to detect motion in a room. Combined with an ESP32, they provide extremely fast, local, cloud-free motion detection that integrates perfectly with Home Assistant. This guide…

DS18B20 digital temperature probe lets you precisely measure temperatures in wet environments with a simple 1-Wire interface. The DS18B20 provides 9 to 12-bit (configurable) temperature readings over a 1-Wire interface, so that only one wire (and ground) needs to be…

The SHT45 is currently one of the most accurate temperature and humidity sensors available.It offers laboratory-grade precision, ultra-low power consumption, and very stable measurements. This guide shows you how to connect an ESP32 + SHT45 to Home Assistant using two…