When implementing a certain input and output that requires GPIO, we found that the available GPIOs on the 40-pin connector are relatively few. The available GPIOs can be seen in the Docs link.https://docs.khadas.com/products/sbc/vim3/applications/gpio/40pin-header

To achieve this, we have removed the original functionality of the pin and enabled GPIO control. This way, any pins you don't need can be fully utilized to expand more GPIOs.

In the Settings menu, there is an option called Pin Multiple.

Among the limited available pins, we can set the SPDIF, UART, and I2S groups as GPIOs for use when they are not in use.

By default, we enable the original functionality of the corresponding pins. When we need to use them as GPIOs, we can disable their function in the interface, and then restart the device to use the GPIO functionality of the corresponding pins.