esp-idf/examples/peripherals/i2s/i2s_basic/i2s_pdm/main/Kconfig.projbuild

menu "I2S PDM Example Configuration"

    choice EXAMPLE_PDM_DIR
        prompt "I2S PDM direction"
        default EXAMPLE_PDM_TX
        help
            Select example PDM direction

        config EXAMPLE_PDM_TX
            bool "PDM TX"
            depends on SOC_I2S_SUPPORTS_PDM_TX
            help
                PDM TX example will play 'twinkle twinkle little star' in three tones.

        config EXAMPLE_PDM_RX
            bool "PDM RX"
            depends on SOC_I2S_SUPPORTS_PDM_RX
            help
                PDM RX example will show the received data from a PDM microphone.
    endchoice

    choice EXAMPLE_PDM_TX_LINE_MODE
        prompt "I2S PDM TX Line Mode"
        depends on EXAMPLE_PDM_TX && SOC_I2S_HW_VERSION_2
        default EXAMPLE_PDM_TX_CODEC
        help
            Decide to output PDM signal into a PDM codec or a low-pass filter

        config EXAMPLE_PDM_TX_CODEC
            bool "Codec line mode"
            help
                Output PDM signal to a PDM codec. The PDM clock signal is mandatory for PDM codec,
                the codec can differentiate the left and right sound channels by sampling data
                on positive or negative edges. That means the data of the left and right channels
                can coexist on a same data line.

        config EXAMPLE_PDM_TX_DAC
            bool "DAC line mode"
            help
                Output PDM signal to a low-pass filter, so that the low-pass filter can restore the PDM
                signal to analog wave. Therefore, each data line can only contains one sound channel,
                if both left and right channels are required, two data lines should be specified as well.
                Normally the PDM signal is not sufficient in DAC line mode.
    endchoice

endmenu