I’ll add a 4-pin I2C expansion header with 3.3 V power, ground, SDA on GPIO6, and SCL on GPIO7. I’ll verify the current terminal names first, then attempt the schematic edit if permissions allow it.

I’m blocked because this project is still view-only, so I can’t add the 4-pin I2C header or create the nets.

Once you have edit access or fork/copy the project, I can add the header with this pinout:

Design note: I2C normally also needs one pair of pull-up resistors, typically 4.7 kΩ from SDA and SCL to VCC_3V3, unless the attached I2C module already includes them.

I’ll add a 4-pin UART header with power, ground, TX on GPIO21, and RX on GPIO20. I’ll verify the existing XIAO terminal names first, then attempt the edit if permissions allow it.

I’m blocked because this project is still view-only, so I can’t add the UART header or create the nets.

Once you have edit access or fork/copy the project, I can add the 4-pin UART header with:

Note: use 3.3 V UART logic with the ESP32-C3; don’t connect a 5 V UART adapter directly to GPIO20/GPIO21.