teensy-sdfat/examples/wipe/wipe.ino

// Example to wipe all data from an already formatted SD.
#include <SPI.h>
#include "SdFat.h"
const int chipSelect = SS;

SdFat sd;

void setup() {
  int c;
  Serial.begin(9600);
  // Wait for USB Serial 
  while (!Serial) {
    SysCall::yield();
  }
  Serial.println("Type 'Y' to wipe all data.");
  while (!Serial.available()) {
    SysCall::yield();
  }
  c = Serial.read();
  if (c != 'Y') {
    sd.errorHalt("Quitting, you did not type 'Y'.");
  }
  // 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();
  }
  // Use wipe() for no dot progress indicator.
  if (!sd.wipe(&Serial)) {
    sd.errorHalt("Wipe failed.");
  }
  // Must reinitialize after wipe.
  // 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.errorHalt("Second init failed.");
  }
  Serial.println("Done");
}

void loop() {
}