teensy-sdfat/SdFat/examples/TwoCards/TwoCards.ino

/*
 * Warning This example requires extra RAM and may crash on Uno.
 * Example use of two SD cards.
 */
#include <SPI.h>
#include "SdFat.h"
#include "FreeStack.h"

SdFat sd1;
const uint8_t SD1_CS = 10;  // chip select for sd1

SdFat sd2;
const uint8_t SD2_CS = 4;   // chip select for sd2

const uint8_t BUF_DIM = 100;
uint8_t buf[BUF_DIM];

const uint32_t FILE_SIZE = 1000000;
const uint16_t NWRITE = FILE_SIZE/BUF_DIM;
//------------------------------------------------------------------------------
// print error msg, any SD error codes, and halt.
// store messages in flash
#define errorExit(msg) errorHalt(F(msg))
#define initError(msg) initErrorHalt(F(msg))
//------------------------------------------------------------------------------
void setup() {
  Serial.begin(9600);
  // Wait for USB Serial 
  while (!Serial) {
    SysCall::yield();
  }
  Serial.print(F("FreeStack: "));

  Serial.println(FreeStack());

  // fill buffer with known data
  for (size_t i = 0; i < sizeof(buf); i++) {
    buf[i] = i;
  }

  Serial.println(F("type any character to start"));
  while (!Serial.available()) {
    SysCall::yield();
  }

  // disable sd2 while initializing sd1
  pinMode(SD2_CS, OUTPUT);
  digitalWrite(SD2_CS, HIGH);

  // initialize the first card
  if (!sd1.begin(SD1_CS)) {
    sd1.initError("sd1:");
  }
  // create Dir1 on sd1 if it does not exist
  if (!sd1.exists("/Dir1")) {
    if (!sd1.mkdir("/Dir1")) {
      sd1.errorExit("sd1.mkdir");
    }
  }
  // initialize the second card
  if (!sd2.begin(SD2_CS)) {
    sd2.initError("sd2:");
  }
// create Dir2 on sd2 if it does not exist
  if (!sd2.exists("/Dir2")) {
    if (!sd2.mkdir("/Dir2")) {
      sd2.errorExit("sd2.mkdir");
    }
  }
  // list root directory on both cards
  Serial.println(F("------sd1 root-------"));
  sd1.ls();
  Serial.println(F("------sd2 root-------"));
  sd2.ls();

  // make /Dir1 the default directory for sd1
  if (!sd1.chdir("/Dir1")) {
    sd1.errorExit("sd1.chdir");
  }

  // make /Dir2 the default directory for sd2
  if (!sd2.chdir("/Dir2")) {
    sd2.errorExit("sd2.chdir");
  }

  // list current directory on both cards
  Serial.println(F("------sd1 Dir1-------"));
  sd1.ls();
  Serial.println(F("------sd2 Dir2-------"));
  sd2.ls();
  Serial.println(F("---------------------"));

  // remove rename.bin from /Dir2 directory of sd2
  if (sd2.exists("rename.bin")) {
    if (!sd2.remove("rename.bin")) {
      sd2.errorExit("remove rename.bin");
    }
  }
  // set the current working directory for open() to sd1
  sd1.chvol();

  // create or open /Dir1/test.bin and truncate it to zero length
  SdFile file1;
  if (!file1.open("test.bin", O_RDWR | O_CREAT | O_TRUNC)) {
    sd1.errorExit("file1");
  }
  Serial.println(F("Writing test.bin to sd1"));

  // write data to /Dir1/test.bin on sd1
  for (uint16_t i = 0; i < NWRITE; i++) {
    if (file1.write(buf, sizeof(buf)) != sizeof(buf)) {
      sd1.errorExit("sd1.write");
    }
  }
  // set the current working directory for open() to sd2
  sd2.chvol();

  // create or open /Dir2/copy.bin and truncate it to zero length
  SdFile file2;
  if (!file2.open("copy.bin", O_WRITE | O_CREAT | O_TRUNC)) {
    sd2.errorExit("file2");
  }
  Serial.println(F("Copying test.bin to copy.bin"));

  // copy file1 to file2
  file1.rewind();
  uint32_t t = millis();

  while (1) {
    int n = file1.read(buf, sizeof(buf));
    if (n < 0) {
      sd1.errorExit("read1");
    }
    if (n == 0) {
      break;
    }
    if ((int)file2.write(buf, n) != n) {
      sd2.errorExit("write2");
    }
  }
  t = millis() - t;
  Serial.print(F("File size: "));
  Serial.println(file2.fileSize());
  Serial.print(F("Copy time: "));
  Serial.print(t);
  Serial.println(F(" millis"));
  // close test.bin
  file1.close();
  file2.close(); 
  // list current directory on both cards
  Serial.println(F("------sd1 -------"));
  sd1.ls("/", LS_R | LS_DATE | LS_SIZE);
  Serial.println(F("------sd2 -------"));
  sd2.ls("/", LS_R | LS_DATE | LS_SIZE);
  Serial.println(F("---------------------"));
  Serial.println(F("Renaming copy.bin"));
  // rename the copy
  if (!sd2.rename("copy.bin", "rename.bin")) {
    sd2.errorExit("sd2.rename");
  }
  // list current directory on both cards
  Serial.println(F("------sd1 -------"));
  sd1.ls("/", LS_R | LS_DATE | LS_SIZE);
  Serial.println(F("------sd2 -------"));
  sd2.ls("/", LS_R | LS_DATE | LS_SIZE);
  Serial.println(F("---------------------"));
  Serial.println(F("Done"));
}
//------------------------------------------------------------------------------
void loop() {}