Indoor air quality (IAQ) is influenced not only by CO₂ and humidity, but also by volatile organic compounds (VOCs) such as cooking fumes, cleaning chemicals, paints, perfumes, and off-gassing from furniture.The SGP40 is a high-quality VOC sensor from Sensirion that…
Sensirion’s SHT-series sensors are considered the gold standard in temperature and humidity sensing.They are used in industrial HVAC, medical devices, consumer electronics, environmental monitoring, and high-accuracy IoT projects. This article compares all SHT sensors, highlighting accuracy, stability, power consumption, differences,…
Bosch Sensortec is the leader in environmental sensing for IoT, and their BMP/BME sensors are used everywhere—from drones and weather stations to air-quality monitors and smart-home automation.Although many modules look identical, each generation offers different capabilities, accuracy improvements, and target…
The ESP32 family has grown massively since the original ESP-WROOM-32 module.Today we have dozens of chips, modules, and development boards, each optimized for different use-cases—from Wi-Fi/BLE automation to AI-enabled audio processing and ultra-low-power IoT nodes. This guide provides a complete…
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…
Bluetooth Low Energy (BLE) sensors such as the Xiaomi Mi Temperature, Inkbird, Switchbot, and many others are extremely popular for Home Assistant users.However, Bluetooth range is limited, and placing Home Assistant in a central location may not always be possible.…
I²C is one of the easiest ways to send data between microcontrollers. ESP32 and ESP8266 both support hardware I²C, and you can connect them directly using just two wires: SDA and SCL and common GND. This guide shows a complete…
ESP-NOW is a fast, connectionless communication protocol developed by Espressif. It allows ESP32 boards to exchange small packets (up to 250 bytes) with extremely low latency and very little overhead — perfect for sensors, dashboards, wireless controllers, and battery-powered devices.…