I2S/I2C/PCM
时间: 2024-03-18 16:37:37 浏览: 14
I2S、I2C和PCM是常见的数字通信接口协议,用于在电子设备之间传输数据。下面是对它们的简要介绍:
1. I2S(Inter-IC Sound):I2S是一种用于音频数据传输的串行接口协议。它通常用于连接音频编解码器、数字信号处理器和音频接口芯片等设备。I2S协议使用三根线进行数据传输,包括一个时钟线、一个数据线和一个帧同步线。时钟线用于同步数据传输,数据线用于传输音频数据,帧同步线用于标识数据的起始和结束。
2. I2C(Inter-Integrated Circuit):I2C是一种用于连接集成电路芯片之间的串行通信协议。它使用两根线进行数据传输,包括一个时钟线和一个数据线。I2C协议支持多主机和多从机的通信方式,可以连接多个设备在同一总线上进行通信。I2C协议具有简单、灵活和可扩展的特点,广泛应用于各种电子设备中。
3. PCM(Pulse Code Modulation):PCM是一种用于模拟信号数字化的编码方式。它将模拟信号按照一定的采样率进行采样,并将每个采样值转换为对应的数字代码。PCM编码后的数字数据可以通过各种数字通信接口进行传输和处理。PCM编码常用于音频和语音信号的数字化,例如CD音频、电话通信等。
相关问题
esp32 s3 读取sd卡音频文件并通过i2s输出
要通过ESP32-S3读取SD卡中的音频文件,并通过I2S输出,请按照以下步骤操作:
1. 首先,您需要将SD卡连接到ESP32-S3。您可以使用SPI协议连接SD卡,或使用ESP32-S3的SDMMC主机控制器。请确保正确配置SD卡相关引脚和协议。
2. 接下来,您需要使用ESP-IDF中的I2S驱动程序将音频数据从SD卡读取并通过I2S输出。您可以使用i2s_write_expand()函数来将16位PCM音频数据转换为I2S数据格式,并使用i2s_write()函数将数据发送到I2S总线。
3. 在使用I2S驱动程序之前,请确保正确配置I2S接口。您可以使用i2s_driver_install()函数安装I2S驱动程序,并使用i2s_set_pin()函数设置I2S引脚。请参考ESP-IDF文档以获取更多详细信息。
4. 最后,您需要编写代码来打开音频文件并从SD卡读取数据。您可以使用ESP-IDF中的文件系统API来访问SD卡上的文件,例如fopen()、fread()和fclose()函数。请确保正确处理文件读取错误和文件结束条件。
下面是一个示例代码片段,用于从SD卡中读取16位PCM音频文件,并将其发送到I2S总线:
```c
#include "esp_partition.h"
#include "esp_vfs_fat.h"
#include "driver/i2s.h"
#define I2S_NUM 0
#define I2S_SAMPLE_RATE 44100
#define I2S_SAMPLE_BITS 16
#define I2S_CHANNEL_NUM 2
#define I2S_DMA_BUF_COUNT 8
void app_main()
{
// 初始化I2S接口
i2s_config_t i2s_config = {
.mode = I2S_MODE_MASTER | I2S_MODE_TX,
.sample_rate = I2S_SAMPLE_RATE,
.bits_per_sample = I2S_SAMPLE_BITS,
.channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,
.communication_format = I2S_COMM_FORMAT_I2S,
.dma_buf_count = I2S_DMA_BUF_COUNT,
.dma_buf_len = 1024,
.intr_alloc_flags = 0,
};
i2s_pin_config_t i2s_pin_config = {
.bck_io_num = 26,
.ws_io_num = 25,
.data_out_num = 33,
.data_in_num = I2S_PIN_NO_CHANGE,
};
i2s_driver_install(I2S_NUM, &i2s_config, 0, NULL);
i2s_set_pin(I2S_NUM, &i2s_pin_config);
// 初始化SD卡
esp_vfs_fat_sdmmc_mount_config_t mount_config = {
.format_if_mount_failed = true,
.max_files = 5,
};
sdmmc_host_t host = SDMMC_HOST_DEFAULT();
sdmmc_slot_config_t slot_config = SDMMC_SLOT_CONFIG_DEFAULT();
esp_vfs_fat_sdmmc_mount("/sdcard", &host, &slot_config, &mount_config, NULL);
// 打开音频文件
FILE* f = fopen("/sdcard/test.pcm", "rb");
if (!f) {
printf("failed to open file\n");
return;
}
// 读取数据并发送到I2S总线
int16_t buf[1024];
size_t read_len;
while ((read_len = fread(buf, sizeof(int16_t), 1024, f)) > 0) {
size_t i2s_len = read_len * 2;
uint8_t i2s_buf[i2s_len];
i2s_write_expand(I2S_NUM, buf, read_len, I2S_SAMPLE_BITS, i2s_buf, i2s_len);
i2s_write(I2S_NUM, i2s_buf, i2s_len, portMAX_DELAY);
}
// 关闭文件和卸载SD卡
fclose(f);
esp_vfs_fat_sdmmc_unmount();
}
```
请注意,以上代码仅供参考,并且可能需要根据您的具体用例进行修改。另外,读取和发送音频数据时需要使用合适的缓冲区大小和数量,以避免数据溢出和下溢。
STM32 用I2S和DMA控制CS4344播放WAVE音频详细程序
以下是一个使用STM32的I2S和DMA控制CS4344播放WAVE音频的详细程序:
```c
#include "stm32f4xx.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_spi.h"
#include "stm32f4xx_dma.h"
#include "wave.h"
#define AUDIO_BUFFER_SIZE 2048
static uint16_t audio_buffer[AUDIO_BUFFER_SIZE];
static uint32_t audio_buffer_index = 0;
static uint32_t audio_buffer_size = 0;
void RCC_Configuration(void)
{
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3, ENABLE);
}
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_12 | GPIO_Pin_15;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOC, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOC, GPIO_PinSource10, GPIO_AF_SPI3);
GPIO_PinAFConfig(GPIOC, GPIO_PinSource12, GPIO_AF_SPI3);
GPIO_PinAFConfig(GPIOC, GPIO_PinSource15, GPIO_AF_SPI3);
}
void SPI_Configuration(void)
{
SPI_InitTypeDef SPI_InitStructure;
SPI_I2S_DeInit(SPI3);
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
SPI_InitStructure.SPI_DataSize = SPI_DataSize_16b;
SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_2;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial = 7;
SPI_Init(SPI3, &SPI_InitStructure);
SPI_Cmd(SPI3, ENABLE);
}
void DMA_Configuration(void)
{
DMA_InitTypeDef DMA_InitStructure;
DMA_DeInit(DMA1_Stream7);
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&SPI3->DR;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)audio_buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
DMA_InitStructure.DMA_BufferSize = AUDIO_BUFFER_SIZE;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA1_Stream7, &DMA_InitStructure);
DMA_ITConfig(DMA1_Stream7, DMA_IT_TC, ENABLE);
NVIC_EnableIRQ(DMA1_Stream7_IRQn);
}
void DMA1_Stream7_IRQHandler(void)
{
if (DMA_GetITStatus(DMA1_Stream7, DMA_IT_TCIF7) != RESET) {
DMA_ClearITPendingBit(DMA1_Stream7, DMA_IT_TCIF7);
audio_buffer_index += AUDIO_BUFFER_SIZE;
audio_buffer_size -= AUDIO_BUFFER_SIZE;
if (audio_buffer_size < AUDIO_BUFFER_SIZE) {
DMA_Cmd(DMA1_Stream7, DISABLE);
SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Tx, DISABLE);
}
}
}
void CS4344_Init(void)
{
GPIO_SetBits(GPIOA, GPIO_Pin_4);
uint16_t reg = 0x0000; // DAC control register
reg |= 0x0001; // Soft reset
reg |= 0x0002; // Power up
reg |= 0x0020; // I2S mode
reg |= 0x0080; // Master mode
reg |= 0x0100; // 24-bit data
reg |= 0x0200; // BCLK is input to DAC
reg |= 0x0800; // MCLK is input to DAC
reg |= 0x1000; // Left channel DAC data is left-justified
reg |= 0x2000; // Right channel DAC data is right-justified
reg |= 0x4000; // Soft mute disable
CS4344_WriteReg(reg);
}
void CS4344_WriteReg(uint16_t reg)
{
GPIO_ResetBits(GPIOA, GPIO_Pin_4);
SPI_I2S_SendData(SPI3, (reg >> 8) & 0xFF);
while (SPI_I2S_GetFlagStatus(SPI3, SPI_I2S_FLAG_BSY) == SET);
SPI_I2S_SendData(SPI3, reg & 0xFF);
while (SPI_I2S_GetFlagStatus(SPI3, SPI_I2S_FLAG_BSY) == SET);
GPIO_SetBits(GPIOA, GPIO_Pin_4);
}
void Wave_Reader(uint8_t *data, uint32_t offset, uint32_t size)
{
uint32_t i;
for (i = 0; i < size; i += 2) {
audio_buffer[i / 2] = (uint16_t)data[offset + i + 1] << 8 | (uint16_t)data[offset + i];
}
}
int main(void)
{
RCC_Configuration();
GPIO_Configuration();
SPI_Configuration();
DMA_Configuration();
CS4344_Init();
uint8_t *wav_data;
uint32_t wav_size;
uint32_t wav_freq;
uint32_t wav_samples;
if (Wave_ReadFile("test.wav", &wav_data, &wav_size, &wav_freq, &wav_samples) != 0) {
// Error reading wave file
while (1);
}
audio_buffer_size = AUDIO_BUFFER_SIZE;
Wave_Reader(wav_data, 44, AUDIO_BUFFER_SIZE * sizeof(uint16_t));
audio_buffer_index = AUDIO_BUFFER_SIZE;
DMA_Cmd(DMA1_Stream7, ENABLE);
SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Tx, ENABLE);
while (audio_buffer_size > 0) {
// Wait for DMA to finish
}
free(wav_data);
while (1);
}
```
该程序使用DMA和I2S接口将WAVE格式的音频数据发送到CS4344芯片,实现音频播放功能。其中,Wave_Reader函数用于从WAVE文件中读取音频数据并将其转换为16位PCM格式。CS4344_Init函数用于初始化CS4344芯片的各种寄存器设置。DMA1_Stream7_IRQHandler函数用于处理DMA传输完成中断。在main函数中,程序首先读取WAVE文件中的音频数据,然后将其发送到CS4344芯片。在DMA传输完成后,程序通过轮询等待音频数据的发送完成,直到音频数据全部发送完毕。