ESP32 for All

Single-board computers such as the Raspberry Pi and the Arduino are now commonplace whether in industry or at home, and are gaining popularity. Espressif's ESP8266 has also established itself both within the scene and at Elektor with its comprehensive functionality at a low price. The ESP32 is the new big brother sporting a dual-core processor, Bluetooth, more RAM and I/O extensions.

MQTT (Message Queue Telemetry Transport) is a publish-subscribe-based (one-to-one or one-to-many) messaging protocol oriented to communication with sensors. MQTT architecture follows a star topology with one or more clients or nodes, and a central server — the broker — responsible of managing the network and relaying messages. This project describes an ESP8266-based adapter that allows any electronic device having a serial port to become an MQTT node connected to a Wi-Fi IoT network. A broker is built with a Raspberry Pi.

Rapid prototyping has been the craze for the last five, six years or so. Hundreds, maybe thousands of open source, open hardware platforms have been created by enthusiasts (including Elektor), were published on the Internet and have been entirely forgotten. Well, not entirely... One small group of indomitable boards still holds out against oblivion. These are their stories.