First Commit

libraries/SdFat/examples/examplesV1/VolumeFreeSpace/VolumeFreeSpace.ino

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+/*
+ * This program demonstrates the freeClusterCount() call.
+ */
+#include <SPI.h>
+#include "SdFat.h"
+#include "sdios.h"
+/*
+ * SD chip select pin.  Common values are:
+ *
+ * Arduino Ethernet shield, pin 4.
+ * SparkFun SD shield, pin 8.
+ * Adafruit Datalogging shield, pin 10.
+ * Default SD chip select is the SPI SS pin.
+ */
+const uint8_t chipSelect = SS;
+
+#define TEST_FILE "Cluster.test"
+// file system
+SdFat sd;
+
+// test file
+SdFile file;
+
+// Serial output stream
+ArduinoOutStream cout(Serial);
+//------------------------------------------------------------------------------
+void printFreeSpace() {
+  cout << F("freeClusterCount() call time: ");
+  uint32_t m = micros();
+  uint32_t volFree = sd.vol()->freeClusterCount();
+  cout << micros() - m << F(" micros\n");
+  cout << F("freeClusters: ") <<  volFree << setprecision(3) << endl;
+  float fs = 0.000512*volFree*sd.vol()->blocksPerCluster();
+  cout << F("freeSpace: ") << fs << F(" MB (MB = 1,000,000 bytes)\n\n");
+}
+//------------------------------------------------------------------------------
+void setup() {
+  Serial.begin(9600);
+  // Wait for USB Serial
+  while (!Serial) {
+    yield();
+  }
+  if (!MAINTAIN_FREE_CLUSTER_COUNT) {
+    cout << F("Please edit SdFatConfig.h and set\n");
+    cout << F("MAINTAIN_FREE_CLUSTER_COUNT nonzero for\n");
+    cout << F("maximum freeClusterCount() performance.\n\n");
+  }
+  // F stores strings in flash to save RAM
+  cout << F("Type any character to start\n");
+  while (!Serial.available()) {
+    yield();
+  }
+  // Initialize at the highest speed supported by the board that is
+  // not over 50 MHz. Try a lower speed if SPI errors occur.
+  if (!sd.begin(chipSelect, SD_SCK_MHZ(50))) {
+    sd.initErrorHalt();
+  }
+  // Insure no TEST_FILE.
+  sd.remove(TEST_FILE);
+
+  cout << F("\nFirst call to freeClusterCount scans the FAT.\n\n");
+  printFreeSpace();
+
+  cout << F("Create and write to ") << TEST_FILE << endl;
+  if (!file.open(TEST_FILE, O_WRONLY | O_CREAT)) {
+    sd.errorHalt(F("Create failed"));
+  }
+  file.print(F("Cause a cluster to be allocated"));
+  file.close();
+
+  cout << F("\nSecond freeClusterCount call is faster if\n");
+  cout << F("MAINTAIN_FREE_CLUSTER_COUNT is nonzero.\n\n");
+
+  printFreeSpace();
+
+  cout << F("Remove ") << TEST_FILE << endl << endl;
+  sd.remove(TEST_FILE);
+  printFreeSpace();
+  cout << F("Done") << endl;
+}
+//------------------------------------------------------------------------------
+void loop() {}