How to put MicroPython firmware on a supported Arduino board with Arduino's MicroPython Installer, which boards are on the list, and how to get Arduino C++ back by uploading a sketch.
What Arduino Lab for MicroPython is, how it differs from Arduino IDE 2, how to put MicroPython firmware on a supported board, how the REPL and file transfer work, and how to get back to Arduino C++ when you want the sketch workflow again.
How to compile Arduino sketches on every GitHub push or pull request using Arduino's official Actions (setup-arduino-cli and compile-sketches), including a matrix of board FQBNs.
How to split an App Lab project so Python on Linux handles slow work and Arduino C++ on the microcontroller handles pins, using the App folder layout and the Bridge.
How to install Arduino IDE 2 beside 1.8.19, keep your sketchbook and libraries, reinstall cores if needed, find Serial Monitor and Board Manager in the new window, and only uninstall 1.8 when a project compiles and uploads in 2.
What an App Lab Brick is, how it differs from an Arduino library, how Bricks run beside Python on Linux, and how to add one from the catalog without treating it as magic.
