The ADC2 controller of the ESP32 is used by the WiFi module. The GPIOs connected to the ADC2 controller cannot be used as ADC channels if the WiFi module is enabled. This is clarified by a note in the documentation.
Although ESP32 has four SPI controllers, only two of them can be effectively used (HSP and VSPI). The third one (FSPI) is used for external memory such as flash and PSRAM and can not be used for peripherals. FSPI is therefore removed from the API. In addition, the SPI0_DEV and SPI1_DEV configuration parameters are renamed SPI0_CTRL and SPI1_CTRL to better describe what they define and to avoid confusion with SPI_DEV (0) and SPI_DEV (1).
