如何使用 Arduino ESP32 将数据存储到 microsdcard（软 SPI ）

忘是亡心i 2024-03-30 15:41 73阅读 0赞

esp32从传感器记录的数据或者日志，并将这些数据保存到SD卡中

1.我们将使用图书馆SD卡进行通信。您可以在此处下载：

[https://github.com/nhatuan84/esp32-micro-sdcard][https_github.com_nhatuan84_esp32-micro-sdcard]

![294a5d598fb8f65b70ffdc08b3919bab.png][]

下载后，解压缩并将其解压缩到Arduino文件夹下的库文件夹中：

![788d1055758aaad4da6041a08bd3e408.png][]

2.格式化 microSD 卡：

将 microSD 卡与 ESP32 配合使用时，应先对其进行格式化。

![b0b95d08f0c4904e1b6259509ee215bb.png][]

![295076ae699f82d1814336969867432f.png][]

3.接线方式：

\[ESP32 IO26 – CS(D3) MICROSD\]

\[ESP32 IO14 – MOSI(CMD) MICROSD\]

\[ESP32 IO13 – MISO(D0) MICROSD\]

\[ESP32 IO27 – SCK(SCLK) MICROSD\]

\[ESP32 GND – GND MICROSD\]

\[3.3V – VCC MICROSD\]

![852506d124263fdb917c41645b56f88c.png][]

4.代码以及说明：

\- SD.begin(uint8\_t cs , int8\_t mosi , int8\_t miso , int8\_t sck): initialize library with SPI pins

\- SD.open(filename, FILE\_WRITE): open file for writing

\- SD.open(filename): open file for reading

\- SD.open("/"): open sdcard at root “/”

以下是代码部分：

#include <mySD.h>
    
    ext::File root;
    int a = 0;
    int b = 0,c=0;
    
    void setup()
    {
      Serial.begin(115200);
    
      Serial.print("Initializing SD card...");
      /* 使用软 SPI 引脚初始化 SD 库，如果使用硬 SPI 替换为这个 SD.begin()*/
      if (!SD.begin(26, 14, 13, 27)) {
        Serial.println("initialization failed!");
        return;
      }
      Serial.println("initialization done.");
      /* Begin at the root "/" */
      root = SD.open("/");
      if (root) {    
        printDirectory(root, 0);
    //    读取sd卡中的文件
        root.close();
      } else {
        Serial.println("error opening test.csv");
      }
      /* open "test.csv" for writing */
      root = SD.open("test.csv", FILE_WRITE);
      /* 如果成功打开 -> root != NULL
        然后写字符串“Hello world!”对它
      */
    
      if (root) {
        root.println("1,2,3,4,5");
    
    //    root.println("250,255,255,200,100,250,255,255,200,100,250,255,255,200,100");
        root.flush();
       /* 关闭文件 */
        root.close();
      } else {
        /*  如果文件打开错误，打印错误 */
        Serial.println("error opening test.csv");
      }
      delay(1000);
      /* 写入后重新打开文件并读取 */
      root = SD.open("test.csv");
      if (root) {    
        /* 从文件中读取直到其中没有其他内容 */
        while (root.available()) {
          /* 读取文件并打印到终端 */
          Serial.write(root.read());
        }
        root.close();
      } else {
        Serial.println("error opening test.csv");
      }
      
      Serial.println("done!");
    }
    
    void loop()
    {
      root = SD.open("/");
      if (root) {    
        printDirectory(root, 0);
    //    读取sd卡中的文件
        root.close();
      } else {
        Serial.println("error opening test.csv");
      }
      /* open "test.csv" for writing */
      root = SD.open("test.csv", FILE_WRITE);
      /* 如果成功打开 -> root != NULL
        然后写字符串“Hello world!”对它
      */
    
      if (root) {
    //    root.println("1,2,3,4,5");
    
        root.println("250,255,255,200,100,250,255,255,200,100,250,255,255,200,100,255,255,200,100,250,255,255,200,100,250");
        root.flush();
       /* 关闭文件 */
        root.close();
      } else {
        /*  如果文件打开错误，打印错误 */
        Serial.println("error opening test.csv");
      }
      delay(1000);
      /* 写入后重新打开文件并读取 */
      root = SD.open("test.csv");
      if (root) {    
        /* 从文件中读取直到其中没有其他内容 */
        while (root.available()) {
          /* 读取文件并打印到终端 */
          c=1;
          if (c == 1){
            a = micros();
            }
          Serial.write(root.read());
        }
        b = micros();
        Serial.print(b - a );
        root.close();
      } else {
        Serial.println("error opening test.csv");
      }
      
      Serial.println("done!");
    }
    void printDirectory(ext::File dir, int numTabs) {
      
      while(true) {
         ext::File entry =  dir.openNextFile();
         if (! entry) {
           break;
         }
         for (uint8_t i=0; i<numTabs; i++) {
           Serial.print('\t');   // we'll have a nice indentation
         }
         // Print the name
         Serial.print(entry.name());
         /*   递归目录，否则打印文件大小 */
         if (entry.isDirectory()) {
           Serial.println("/");
           printDirectory(entry, numTabs+1);
         } else {
           /*   files have sizes, directories do not */
           Serial.print("\t\t");
           Serial.println(entry.size());
         }
         entry.close();
       }
    }

5.打开串口监视器，查看文件已经成功输入：

![0cf1bc7a50dbe450a9a9dfd8baa1e7a4.png][]

6.打开csv文件，内容已经写入：

![36127a03a66dfce1a686e3c9667c1e56.png][]

文章参考来源：[Demo 7: How to use Arduino ESP32 to store data to microsdcard (Soft SPI and Hard SPI) (iotsharing.com)][Demo 7_ How to use Arduino ESP32 to store data to microsdcard _Soft SPI and Hard SPI_ _iotsharing.com]

[https_github.com_nhatuan84_esp32-micro-sdcard]: https://github.com/nhatuan84/esp32-micro-sdcard
[294a5d598fb8f65b70ffdc08b3919bab.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/8896b604a8894bd9ae917a28b8c476d9.png
[788d1055758aaad4da6041a08bd3e408.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/9691046182b940d99600ae01d19388cb.png
[b0b95d08f0c4904e1b6259509ee215bb.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/e658b2ac454d4e4abb96bf1e2065b6c9.png
[295076ae699f82d1814336969867432f.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/7f9552e5a4f44695a9177725ebbeffea.png
[852506d124263fdb917c41645b56f88c.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/0fc05c79e5894d33bcebe865861fe122.png
[0cf1bc7a50dbe450a9a9dfd8baa1e7a4.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/f3b4b2d3ac334cf6ae57d83fc95c43d5.png
[36127a03a66dfce1a686e3c9667c1e56.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/1295a2e3b5c04d12ba2af03cc9bcca9e.png
[Demo 7_ How to use Arduino ESP32 to store data to microsdcard _Soft SPI and Hard SPI_ _iotsharing.com]: http://www.iotsharing.com/2017/05/how-to-use-arduino-esp32-to-store-data-to-sdcard.html