microsd
SD卡读取示例

示例功能:作为单片机连接MicroSD卡的桥梁,以下示例是通过驱动程序,读取MicroSD卡的信息,该模块主要实现: 1.存储扩展:为嵌入式设备增加大容量存储(GB级) 2.数据持久化:断电后仍能保存关键数据 3.文件交互:支持FAT文件系统的读写操作 硬件连接(默认已连接详细参考表格:引脚占用表)

ESP32-S3 | SD卡模块
GPIO3 | CLK GPIO35 | MISO GPIO14 | MOSI GPIO46 | CS 3.3V | V GND | G
示例代码:
#include <SPI.h>
#include <SD.h>
// 配置SPI引脚
#define PIN_SPI_MISO 35
#define PIN_SPI_MOSI 14
#define PIN_SPI_CLK 3
#define PIN_CS 46
SPIClass spi(HSPI); // 使用HSPI(可自定义)
void setup() {
Serial.begin(115200);
while (!Serial); // 等待串口连接(仅用于调试)
spi.begin(PIN_SPI_CLK, PIN_SPI_MISO, PIN_SPI_MOSI, PIN_CS); // 初始化SPI
Serial.print("Initializing SD card...");
if (!SD.begin(PIN_CS, spi)) { // 初始化SD卡
Serial.println("initialization failed!");
while (1);
}
Serial.println("initialization done.");
// 列出根目录内容
listDir(SD, "/", 0);
// 示例:读取测试文件
readFile(SD, "/test.txt");
}
void loop() {
// 空循环
}
// 列出目录内容
void listDir(fs::FS &fs, const char * dirname, uint8_t levels){
Serial.printf("Listing directory: %s\n", dirname);
File root = fs.open(dirname);
if(!root){
Serial.println("Failed to open directory");
return;
}
if(!root.isDirectory()){
Serial.println("Not a directory");
return;
}
File file = root.openNextFile();
while(file){
if(file.isDirectory()){
Serial.print(" DIR : ");
Serial.println(file.name());
if(levels){
listDir(fs, file.name(), levels -1);
}
} else {
Serial.print(" FILE: ");
Serial.print(file.name());
Serial.print(" SIZE: ");
Serial.println(file.size());
}
file = root.openNextFile();
}
}
// 读取文件内容
void readFile(fs::FS &fs, const char * path){
Serial.printf("Reading file: %s\n", path);
File file = fs.open(path);
if(!file){
Serial.println("Failed to open file for reading");
return;
}
Serial.print("Read from file: ");
while(file.available()){
Serial.write(file.read());
}
file.close();
}
注意事项:microSD模块引脚直接与扩展板的引脚连接,个别引脚的连接,可能会导致程序上传失败,在下载程序时可以不插microSD卡或者将主板从扩展板接口中拔取下再上传程序。 进阶示例:使用麦克风模块录制MP3文件,随后存入microSD卡中。
#include "Arduino.h"
#include "driver/i2s.h"
#include "FS.h"
#include "SD.h"
#include "SPI.h"
// 🎤 PDM 麦克风(I2S)
#define I2S_WS 42 // WS / LRCK (可更改)
#define I2S_BCLK 41 // BCLK (可更改)
#define I2S_DIN 2 // DIN (可更改)
// 💾 SD 卡(SPI)
#define SD_CS 46 // CS (可更改)
#define SD_SCK 3 // SCK
#define SD_MOSI 14 // MOSI
#define SD_MISO 35 // MISO
// 创建 SPI 实例
SPIClass spi = SPIClass(FSPI); // FSPI 是 ESP32-S3 上的主 SPI 端口
#define SAMPLE_RATE 16000 // 采样率 (Hz)
#define BUFFER_SIZE 512 // 采样缓冲区大小
#define RECORD_TIME 10 // 录音时长 (秒)
File audioFile;
int16_t sampleBuffer[BUFFER_SIZE];
void setup() {
Serial.begin(115200);
Serial.println("🎤 MSM261S4030H0R PDM 录音测试...");
// 初始化 I2S
i2s_config_t i2s_config = {
.mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
.sample_rate = SAMPLE_RATE,
.bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
.channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
.communication_format = I2S_COMM_FORMAT_STAND_I2S,
.intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
.dma_buf_count = 8,
.dma_buf_len = BUFFER_SIZE
};
i2s_pin_config_t pin_config = {
.bck_io_num = I2S_BCLK,
.ws_io_num = I2S_WS,
.data_out_num = I2S_PIN_NO_CHANGE,
.data_in_num = I2S_DIN
};
i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
i2s_set_pin(I2S_NUM_0, &pin_config);
// 初始化 SD 卡
SPIClass spi = SPIClass(FSPI);
spi.begin(SD_SCK, SD_MISO, SD_MOSI, SD_CS);
if (!SD.begin(SD_CS, spi, 1000000)) { // 使用自定义的 SPI 总线
Serial.println("❌ 无法挂载 SD 卡!");
return;
}
Serial.println("✅ SD 卡已挂载!");
// 开始录音
recordAudio("/record.wav", RECORD_TIME);
}
void loop() {}
void recordAudio(const char *filename, int duration) {
Serial.printf("🎙 开始录音: %s (%d 秒)...\n", filename, duration);
audioFile = SD.open(filename, FILE_WRITE);
if (!audioFile) {
Serial.println("❌ 无法创建文件!");
return;
}
// 写入 WAV 头
writeWavHeader(audioFile, SAMPLE_RATE, 16, 1);
size_t bytesRead;
int totalSamples = SAMPLE_RATE * duration;
int samplesWritten = 0;
while (samplesWritten < totalSamples) {
i2s_read(I2S_NUM_0, sampleBuffer, sizeof(sampleBuffer), &bytesRead, portMAX_DELAY);
audioFile.write((uint8_t *)sampleBuffer, bytesRead);
samplesWritten += (bytesRead / 2);
Serial.printf("📀 已录制: %d / %d 采样点\n", samplesWritten, totalSamples);
}
// 结束录音,更新 WAV 头
updateWavHeader(audioFile);
audioFile.close();
Serial.println("✅ 录音完成!");
}
void writeWavHeader(File &file, uint32_t sampleRate, uint16_t bitDepth, uint16_t channels) {
uint32_t fileSize = 44; // 先写入 WAV 头部,后续再更新文件大小
uint32_t dataSize = 0; // 数据区大小
file.seek(0);
file.write((const uint8_t *)"RIFF", 4);
file.write((uint8_t *)&fileSize, 4);
file.write((const uint8_t *)"WAVE", 4);
file.write((const uint8_t *)"fmt ", 4);
uint32_t subchunk1Size = 16;
file.write((uint8_t *)&subchunk1Size, 4);
uint16_t audioFormat = 1;
file.write((uint8_t *)&audioFormat, 2);
file.write((uint8_t *)&channels, 2);
file.write((uint8_t *)&sampleRate, 4);
uint32_t byteRate = sampleRate * channels * (bitDepth / 8);
file.write((uint8_t *)&byteRate, 4);
uint16_t blockAlign = channels * (bitDepth / 8);
file.write((uint8_t *)&blockAlign, 2);
file.write((uint8_t *)&bitDepth, 2);
file.write((const uint8_t *)"data", 4);
file.write((uint8_t *)&dataSize, 4);
}
void updateWavHeader(File &file) {
uint32_t fileSize = file.size() - 8;
uint32_t dataSize = file.size() - 44;
file.seek(4);
file.write((uint8_t *)&fileSize, 4);
file.seek(40);
file.write((uint8_t *)&dataSize, 4);
}