利用arduino IDE 1.8.9做ESP32的开发，无法将资料写入SD卡中是为什么？

#include
#include
#include
BluetoothSerial SerialBT;
int key;
#define SD_CS 34



void setup()
{
  Serial.begin(115200);
  SerialBT.begin("ESP32");
  

  SD.begin(SD_CS);  
  if(!SD.begin(SD_CS)) {
    Serial.println("Card Mount Failed");
    return;
  }
  uint8_t cardType = SD.cardType();
  if(cardType == CARD_NONE) {
    Serial.println("No SD card attached");
    return;
  }
  Serial.println("Initializing SD card...");
  if (!SD.begin(SD_CS)) {
    Serial.println("ERROR - SD card initialization failed!");
    return;    // init failed
  }

  // If the data.txt file doesn't exist
  // Create a file on the SD card and write the data labels
  File file = SD.open("data.txt");
  if(!file) {
    Serial.println("File doens't exist");
    Serial.println("Creating file...");
    writeFile(SD, "data.txt", "data rn");
  }
  else {
    Serial.println("File already exists");  
  }
  file.close();




}

void loop()
{

  int value =0;
  
  int D0 = digitalRead(2);
  int D1 = digitalRead(15);
  int D2 = digitalRead(4);
  int D3 = digitalRead(16);
  int D4 = digitalRead(17);
  int D5 = digitalRead(5);
  int D6 = digitalRead(18);
  int D7 = digitalRead(19);
  char val[256];
  snprintf(val , sizeof(val) , "%d %d %d %d %d %d %d %d",
           D0,D1,D2,D3,D4,D5,D6,D7);
   
   Serial.println(val);

  byte Date[8];
  Date[0] = D0;
  Date[1] = D1;
  Date[2] = D2;
  Date[3] = D3;
  Date[4] = D4;
  Date[5] = D5;
  Date[6] = D6;
  Date[7] = D7;

  readFromAPP();   
  if(key == 65)
  {
    SerialBT.write('B');
    for(int i=0;i<8;i++)
    {
      SerialBT.write(Date[i]);
      delay(10);
   
    }
    key = 0;
   
  }
  delay(100);
  appendFile(SD, "data.txt", val);
}



void readFromAPP()
{
  while (SerialBT.available() > 0)
  {
   key = SerialBT.read();
  }
}

void appendFile(fs::FS &fs, const char * path, const char * message) {
  Serial.printf("Appending to file: %sn", path);

  File file = fs.open(path, FILE_APPEND);
  if(!file) {
    Serial.println("Failed to open file for appending");
    return;
  }
  if(file.print(message)) {
    Serial.println("Message appended");
  } else {
    Serial.println("Append failed");
  }
  file.close();
}

void writeFile(fs::FS &fs, const char * path, const char * message) {
  Serial.printf("Writing file: %sn", path);

  File file = fs.open(path, FILE_WRITE);
  if(!file) {
    Serial.println("Failed to open file for writing");
    return;
  }
  if(file.print(message)) {
    Serial.println("File written");
  } else {
    Serial.println("Write failed");
  }
  file.close();
}

我是位初学者利用arduino IDE 1.8.9做ESP32的开发
以上是我的程式码我在製作将8个脚位的状态透过蓝芽传输并用SD卡纪录
我一直无法将资料【val】写入我的SD卡中
我将模组CS脚位连接到开发版34脚内
程式编译没问题但我一直没办法将我的资料【val】写入SD卡内
我想知道为什么及如何修改