一、參考原理圖
1、INMP441
2、STM32
注意INMP441的第4引腳，用來選擇左聲道還是右聲道。
二、代碼生成
代碼使用cubemx生成
1、iis設(shè)置
2、DMA設(shè)置
3、生成代碼
文章來源：http://www.zghlxwxcb.cn/news/detail-631898.html
三、代碼修改
1、首先定義一個(gè)數(shù)組
#define BUFFER_SIZE (4)
static uint32_t simpleBuf[BUFFER_SIZE];
/* USER CODE BEGIN PV */
uint32_t val24;
int val32;
/* USER CODE END PV */
2、定義接收完成中斷函數(shù)
/* USER CODE BEGIN 0 */
unsigned cb_cnt=0;
//I2S接收完成回調(diào)函數(shù)
void HAL_I2S_RxCpltCallback(I2S_HandleTypeDef *hi2s)
{
if(hi2s==&hi2s2){
cb_cnt++;//回調(diào)次數(shù)計(jì)數(shù)
//將兩個(gè)32整型合并為一個(gè)
//dat32 example: 0000fffb 00004f00
val24=(dma[0]<<8)+(dma[1]>>8);
//將24位有符號(hào)整型擴(kuò)展到32位
if(val24 & 0x800000){//negative
val32=0xff000000 | val24;
}else{//positive
val32=val24;
}
//以采樣頻率的十分之一，串口發(fā)送采樣值
if(cb_cnt%10==0)
printf("%d\r\n",val32);
}
}
/* USER CODE END 0 */
3、啟動(dòng)接收
HAL_I2S_Receive_DMA(&hi2s2,(uint16_t*)simpleBuf,BUFFER_SIZE);
4、完整代碼
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2022 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "dma.h"
#include "i2s.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdio.h>
//#include "stm32f1xx_hal.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
uint32_t dma[4];
uint32_t val24;
int val32;
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
unsigned cb_cnt=0;
//I2S接收完成回調(diào)函數(shù)
void HAL_I2S_RxCpltCallback(I2S_HandleTypeDef *hi2s)
{
if(hi2s==&hi2s2){
cb_cnt++;//回調(diào)次數(shù)計(jì)數(shù)
//將兩個(gè)32整型合并為一個(gè)
//dat32 example: 0000fffb 00004f00
val24=(simpleBuf[0]<<8)+(simpleBuf[1]>>8);
//將24位有符號(hào)整型擴(kuò)展到32位
if(val24 & 0x800000){//negative
val32=0xff000000 | val24;
}else{//positive
val32=val24;
}
//以采樣頻率的十分之一，串口發(fā)送采樣值
if(cb_cnt%10==0)
printf("%d\r\n",val32);
}
}
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USART1_UART_Init();
MX_DMA_Init();
MX_I2S2_Init();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
//開啟DMA傳輸
HAL_I2S_Receive_DMA(&hi2s2,(uint16_t*)simpleBuf,BUFFER_SIZE);
while (1)
{
HAL_Delay(10);
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
//后面都是Cube自動(dòng)生成的代碼，省略
5、代碼解析
根據(jù)以上說明，最后一個(gè)參數(shù)size的單位是由數(shù)據(jù)幀的長度決定的。前面在Cube中設(shè)置的數(shù)據(jù)格式為24 Bits Data on 32 Bits Frame，因此DMA讀取數(shù)據(jù)的總長度為size×4字節(jié)。前面定義的DMA緩沖區(qū)是一個(gè)長度為4的uint32_t型數(shù)組，緩沖區(qū)中的數(shù)據(jù)格式為：前2個(gè)元素表示左聲道數(shù)據(jù)，后2個(gè)表示右聲道數(shù)據(jù)。
單通道數(shù)據(jù)格式為：第一個(gè)字節(jié)：0x00000004 第一個(gè)字節(jié)：0x00004500。通過val24=(dma[0]<<8)+(dma[1]>>8);合成0x00fffb4f ,然后區(qū)分正負(fù)極：文章來源地址http://www.zghlxwxcb.cn/news/detail-631898.html
if(val24 & 0x800000){
val32=0xff000000 | val24;
}else{
val32=val24;
}
到了這里，關(guān)于STM32驅(qū)動(dòng)INMP441麥克風(fēng)實(shí)現(xiàn)左右通道聲音采集的文章就介紹完了。如果您還想了解更多內(nèi)容，請?jiān)谟疑辖撬阉鱐OY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！
