Closed per1234 closed 2 years ago
From the Arduino Sketch Specification: https://arduino.github.io/arduino-cli/dev/sketch-specification/#sketch-folders-and-files
The sketch root folder name and code file names must start with a basic letter (A-Z or a-z) or number (0-9), followed by basic letters, numbers, underscores (_), dots (.) and dashes (-).
From the Arduino Sketch Specification: https://arduino.github.io/arduino-cli/dev/sketch-specification/#sketch-folders-and-files