esp-idf/components/esp_driver_i2s/include/driver/lp_i2s_pdm.h
2024-08-02 12:02:05 +08:00

101 lines
4.5 KiB
C

/*
* SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#pragma once
#include "esp_types.h"
#include "esp_err.h"
#include "driver/i2s_types.h"
#include "hal/i2s_types.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief PDM format in 2 slots(RX)
* @param bits_per_sample I2S data bit width, only support 16 bits for PDM mode
* @param mono_or_stereo I2S_SLOT_MODE_MONO or I2S_SLOT_MODE_STEREO
*/
#define LP_I2S_PDM_RX_SLOT_DEFAULT_CONFIG(bits_per_sample, mono_or_stereo) { \
.data_bit_width = bits_per_sample, \
.slot_bit_width = I2S_SLOT_BIT_WIDTH_AUTO, \
.slot_mode = mono_or_stereo, \
.slot_mask = (mono_or_stereo == I2S_SLOT_MODE_MONO) ? \
I2S_PDM_SLOT_LEFT : I2S_PDM_SLOT_BOTH, \
.hp_en = true, \
.hp_cut_off_freq_hz = 35.5, \
.amplify_num = 1, \
}
/**
* @brief LP I2S pin configurations
*/
typedef struct {
int clk; /*!< clk pin number */
int din; /*!< din pin number */
} lp_i2s_pdm_rx_gpio_config_t;
/*
High Pass Filter Cut-off Frequency Sheet
+----------------+------------------+----------------+------------------+----------------+------------------+
| param0, param5 | cut-off freq(Hz) | param0, param5 | cut-off freq(Hz) | param0, param5 | cut-off freq(Hz) |
+----------------+------------------+----------------+------------------+----------------+------------------+
| (0, 0) | 185 | (3, 3) | 115 | (5, 5) | 69 |
| (0, 1) | 172 | (1, 7) | 106 | (4, 7) | 63 |
| (1, 1) | 160 | (2, 4) | 104 | (5, 6) | 58 |
| (1, 2) | 150 | (4, 4) | 92 | (5, 7) | 49 |
| (2, 2) | 137 | (2, 7) | 91.5 | (6, 6) | 46 |
| (2, 3) | 126 | (4, 5) | 81 | (6, 7) | 35.5 |
| (0, 3) | 120 | (3, 7) | 77.2 | (7, 7) | 23.3 |
+----------------+------------------+----------------+------------------+----------------+------------------+
*/
/**
* @brief I2S slot configuration for PDM RX mode
*/
typedef struct {
/* General fields */
i2s_data_bit_width_t data_bit_width; /*!< I2S sample data bit width (valid data bits per sample), only support 16 bits for PDM mode */
i2s_slot_bit_width_t slot_bit_width; /*!< I2S slot bit width (total bits per slot) , only support 16 bits for PDM mode */
i2s_slot_mode_t slot_mode; /*!< Set mono or stereo mode with I2S_SLOT_MODE_MONO or I2S_SLOT_MODE_STEREO */
/* Particular fields */
i2s_pdm_slot_mask_t slot_mask; /*!< Choose the slots to activate */
bool ws_pol; /*!< WS signal polarity, set true to enable high lever first */
bool hp_en; /*!< High pass filter enable */
float hp_cut_off_freq_hz; /*!< High pass filter cut-off frequency, range 23.3Hz ~ 185Hz, see cut-off frequency sheet above */
uint32_t amplify_num; /*!< The amplification number of the final conversion result.
* The data that have converted from PDM to PCM module, will time `amplify_num` additionally to amplify the final result.
* Note that it's only a multiplier of the digital PCM data, not the gain of the analog signal
* range 1~15, default 1 */
} lp_i2s_pdm_rx_slot_config_t;
/**
* @brief LP I2S PDM configuration
*/
typedef struct {
lp_i2s_pdm_rx_gpio_config_t pin_cfg; /*!< Pin configuration */
lp_i2s_pdm_rx_slot_config_t slot_cfg; /*!< PDM mode slot configuration */
/* LP I2S only support slave mode, not support to configure the clock */
} lp_i2s_pdm_rx_config_t;
/**
* @brief Init LP I2S to PDM mode
*
* @param[in] handle LP I2S channel handle
* @param[in] pdm_cfg PDM configuration
*
* @return
* - ESP_OK: On success
* - ESP_ERR_INVALID_ARG: Invalid argument
* - ESP_ERR_INVALID_STATE: Invalid state
*/
esp_err_t lp_i2s_channel_init_pdm_rx_mode(lp_i2s_chan_handle_t handle, const lp_i2s_pdm_rx_config_t *pdm_cfg);
#ifdef __cplusplus
}
#endif