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

Posted 2021-12-24 perseverance52

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

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• 主要针对使用这个库：github地址：https://github.com/nhatuan84/esp32-micro-sdcard

如果网页无法加载，将域名改为镜像地址的例如：https://hub.fastgit.org/nhatuan84/esp32-micro-sdcard

• 该库支持软SPI接口和硬SPI接口.如果使用硬SPI接口直接定义：

    if (!SD.begin())  
    Serial.println("initialization failed!");
    return;
  

• 如果是软SPI接口就：

  if (!SD.begin(26, 14, 13, 27)) 
    Serial.println("initialization failed!");
    return;
  

接线说明

• 软SPI接口接线方式：

		Soft SPI 
[ESP32 IO26 – CS MICRO SD]
[ESP32 IO14 – MOSI MICRO SD]
[ESP32 IO13 – MISO MICRO SD]
[ESP32 IO27 – SCK MICRO SD]
[ESP32 GND – GND MICRO SD]
[VIN – VCC MICRO SD]

• 硬SPI接口接线方式：

    		Hard SPI
 * MICROSD CS    -    ESP32 IO5
  MICROSD SCK   -     ESP32 IO18
  MICROSD MOSI  -    ESP32 IO23
  MICROSD MISO   -   ESP32 IO19
  MICROSD Vcc   -      ESP32 VIN
  MICROSD GND   -    ESP32 GND

实例代码

#include <mySD.h>

File root;

void setup()

  Serial.begin(115200);

  Serial.print("Initializing SD card...");
  /* initialize SD library with Soft SPI pins, if using Hard SPI replace with this SD.begin()*/
//  if (!SD.begin(26, 14, 13, 27)) //采用软SPI接口
  if (!SD.begin())  采用硬SPI接口
    Serial.println("initialization failed!");
    return;
  
  Serial.println("initialization done.");
  /* Begin at the root "/" */
  root = SD.open("/");
  if (root)     
    printDirectory(root, 0);
    root.close();
   else 
    Serial.println("error opening test.txt");
  
  /* open "test.txt" for writing */
  root = SD.open("test.txt", FILE_WRITE);
  /* if open succesfully -> root != NULL 
    then write string "Hello world!" to it
  */
  if (root) 
    root.println("Hello world!");
    root.flush();
   /* close the file */
    root.close();
   else 
    /* if the file open error, print an error */
    Serial.println("error opening test.txt");
  
  delay(1000);
  /* after writing then reopen the file and read it */
  root = SD.open("test.txt");
  if (root)     
    /* read from the file until there's nothing else in it */
    while (root.available()) 
      /* read the file and print to Terminal */
      Serial.write(root.read());
    
    root.close();
   else 
    Serial.println("error opening test.txt");
  
  
  Serial.println("done!");


void loop()



void printDirectory(File dir, int numTabs) 
  
  while(true) 
     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());
     /* Recurse for directories, otherwise print the file size */
     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();
   

相关接口函数

Class SD:

• -SD.begin(uint8_t cs , int8_t mosi , int8_t miso , int8_t sck): 使用SPI引脚初始化库
• SD.open(filename, FILE_WRITE): 打开文件进行写入
• SD.open(filename): 打开文件进行读取
• SD.open("/"): 打开sdcard at root“/”

Class File:

• openNextFile(): 检查条目是否为目录
• name(): get the name of file or directory
• isDirectory(): check if entry is directory
• size(): 获取文件大小
• println(text): 将文本写入打开的文件
• available(): 检查可用的数据reading
• read(): 如果数据可用则读取数据
• close(): 关闭打开的文件