Here you can find tutorials about microcontrolers (Arduino, ESP8266, ESP32), Raspberry Pi, Orange Pi, Home Automation, 3D printing, Python and IoT development.
Tutorials classified by level of difficulty
Home Automation Tutorials
Gateways and Home Automation protocols
Based on MQTT
Open Source firmware and projects
Development boards, Web Server and Web Client programming
Connected objects (IoT): firmware, servers, languages, dashboards