I2C sensors on the XIAO ESP32S3

Bus pins are fixed by the board: SDA = D4 = GPIO5, SCL = D5 = GPIO6. Wire.begin(D4, D5) — the no-argument form picks the wrong pins.

Read the xiao-esp32s3 skill for the compile/upload workflow, and xiao-serial-monitor for watching the output.

Always scan before writing driver code

Module silkscreens lie and address straps vary between clones. One scan settles both, and everything downstream depends on being right about it:

arduino-cli compile --fqbn esp32:esp32:XIAO_ESP32S3 -u -p <PORT> assets\sketches\i2c_scan