This is an old thread, but I recently ran into the same and wanted to update this with an answer. There are a series of directories under ...esp-matter/device_hal/device that contain the values for the button and the LED for the examples. The main file is device.c which defines the gpio pin. Unfortu...

Follow up - got the latest esp-matter repo and now the ESP32 light example joins via Smartthings commisioning interface. So, success.

I've built the tools and the light example on a generic ESP32 dev kitC but so far I get an error when trying to commission the device.

Just wanted to add that using Bluetooth ALSO disables ADC2 port so GPIOs 0, 2, 4, 12 - 15 and 25 - 27 can't be used with either wifi or bluetooth.