XIAO ESP32S3 via arduino-cli (Windows)

Everything below was verified on real hardware (esp32 core 3.3.10, 2026-07). Follow it literally and you will not need to troubleshoot.

Paths below are relative to this skill's folder. <PORT> is the board's COM port and <SKETCH_DIR> is a sketch folder in the user's workspace.

One-time setup (skip any step that is already true)

arduino-cli version                          # confirm arduino-cli exists
arduino-cli core list                        # is esp32:esp32 3.x installed?
# if not (this downloads ~1 GB and can take several minutes — use a long timeout):
arduino-cli core update-index
arduino-cli core install esp32:esp32

Finding the board