/* * Append Example * * This sketch shows how to use open for append. * The sketch will append 100 line each time it opens the file. * The sketch will open and close the file 100 times. */ #include // SD chip select pin const uint8_t chipSelect = SS_PIN; // file system object SdFat sd; // create Serial stream ArduinoOutStream cout(Serial); // store error strings in flash to save RAM #define error(s) sd.errorHalt_P(PSTR(s)) //------------------------------------------------------------------------------ void setup() { // filename for this example char name[] = "APPEND.TXT"; Serial.begin(9600); // pstr() stores strings in flash to save RAM cout << endl << pstr("Type any character to start\n"); while (Serial.read() < 0) {} // initialize the SD card at SPI_HALF_SPEED to avoid bus errors with // breadboards. use SPI_FULL_SPEED for better performance. if (!sd.init(SPI_HALF_SPEED, chipSelect)) sd.initErrorHalt(); cout << pstr("Appending to: ") << name; for (uint8_t i = 0; i < 100; i++) { // open stream for append ofstream sdout(name, ios::out | ios::app); if (!sdout) error("open failed"); // append 100 lines to the file for (uint8_t j = 0; j < 100; j++) { // use int() so byte will print as decimal number sdout << "line " << int(j) << " of pass " << int(i); sdout << " millis = " << millis() << endl; } // close the stream sdout.close(); if (!sdout) error("append data failed"); // output progress indicator if (i % 25 == 0) cout << endl; cout << '.'; } cout << endl << "Done" << endl; } //------------------------------------------------------------------------------ void loop() {}