• filter_length : frequency_count_configuration_t
• frequency_update_callback : frequency_count_configuration_t
• pcnt_channel : frequency_count_configuration_t
• pcnt_gpio : frequency_count_configuration_t
• pcnt_unit : frequency_count_configuration_t
• rmt_channel : frequency_count_configuration_t
• rmt_clk_div : frequency_count_configuration_t
• rmt_gpio : frequency_count_configuration_t
• rmt_max_blocks : frequency_count_configuration_t
• sampling_period_seconds : frequency_count_configuration_t
• sampling_window_seconds : frequency_count_configuration_t
• window_start_callback : frequency_count_configuration_t