MQTT is the common language of local smart home devices. Zigbee2MQTT, Tasmota, Shelly, ESP boards and many DIY sensors can all publish to a broker on your own network. Node-RED is a visual tool that listens to those messages and reacts to them. Together they make a small, vendor-neutral automation setup that runs on a Raspberry Pi or any Debian or
Wi-Fi HaLow promises something that sounds ideal for a house with a large garden, a detached garage or an allotment: Wi-Fi that reaches about a kilometre, passes through walls and runs a sensor on a battery for months. Modules, Raspberry Pi add-on boards and small routers have started to appear. Before you buy, though, it helps to know that HaLow i
A Raspberry Pi is a popular choice for the box that runs a smart home: a broker, Zigbee2MQTT, Node-RED, an automation platform, maybe a small database. It uses little power and takes little space. When a Pi-based setup dies, though, the cause is rarely the processor. It is usually the SD card, the power supply or heat. This guide covers the hardwar
Measuring temperature and humidity is the most common first project with an ESP32, an Arduino or a Raspberry Pi, and the choice of sensor decides whether the readings are useful. Four families dominate hobby shops: the DHT22 (also sold as AM2302), the Bosch BME280, the Aosong AHT20 and the Sensirion SHT4x. They differ in accuracy, interface and how
Zigbee2MQTT is best known as a Home Assistant add-on, but it does not need Home Assistant at all. At its core it is a bridge: it talks Zigbee to your sensors, bulbs and switches through a USB or network adapter, and publishes everything as MQTT messages. Anything that speaks MQTT can then use those devices: Node-RED, openHAB, a Python script, an ES
ESPHome, Tasmota and the Arduino framework are the usual ways to program an ESP32 for the home, but there is another option that suits people who already know Python: MicroPython. It runs a Python interpreter directly on the microcontroller. You type commands into an interactive prompt (the REPL), see results immediately and copy .py files to the b
Getting a sensor to publish to an MQTT broker takes a few lines of code. Getting a whole house of sensors, switches and scripts to talk over MQTT without stale values, lost commands and devices that look online when they are not takes a little more thought. Four features decide most of it: topic structure, Quality of Service (QoS), retained message
Almost every home-made sensor, relay or LED controller starts with the same question: which Wi-Fi microcontroller board should it be built on? The four most common choices are the veteran ESP8266, the classic ESP32, the smaller RISC-V-based ESP32-C3 and the Raspberry Pi Pico 2 W. They overlap a lot, but the differences matter once you look at memor
An MQTT broker only passes messages along. Once a temperature reading has been delivered, it is gone, apart from the last retained value. If you want to see how the living room temperature changed over the past week, something has to subscribe to the topics, store every reading with a timestamp and draw a chart from it.
