adaloggerFlush.ino

    #include <SPI.h>
    #include <SD.h>

    // Set the pins used
    #define cardSelect 4
    #define switchPin 12

    File logfile;
    bool stopPin = true;

    // blink out an error code
    void error(uint8_t errno) {
      while(1) {
        uint8_t i;
        for (i=0; i<errno; i++) {
          digitalWrite(13, HIGH);
          delay(200);
          digitalWrite(13, LOW);
          delay(200);
        }
        for (i=errno; i<10; i++) {
          delay(500);
        }
      }
    }

    // This line is not needed if you have Adafruit SAMD board package 1.6.2+
    //   #define Serial SerialUSB

    void setup() {
      // connect at 115200 so we can read the GPS fast enough and echo without dropping chars
      // also spit it out
      Serial.begin(9600);
      Serial.println("\r\nAnalog logger test");
      pinMode(13, OUTPUT);


      // see if the card is present and can be initialized:
      if (!SD.begin(cardSelect)) {
        Serial.println("Card init. failed!");
        error(2);
      }
      char filename[15];
      strcpy(filename, "ANALOG00.TXT");
      for (uint8_t i = 0; i < 100; i++) {
        filename[6] = '0' + i/10;
        filename[7] = '0' + i%10;
        // create if does not exist, do not open existing, write, sync after write
        if (! SD.exists(filename)) {
          break;
        }
      }

      logfile = SD.open(filename, FILE_WRITE);
      if( ! logfile ) {
        Serial.print("Couldnt create ");
        Serial.println(filename);
        error(3);
      }
      Serial.print("Writing to ");
      Serial.println(filename);

      pinMode(13, OUTPUT);
      pinMode(8, OUTPUT);
      Serial.println("Ready!");
      pinMode(switchPin, INPUT_PULLUP);
      logfile.println("time, A0");
      Serial.println("time, A0");
    }

    uint8_t i=0;
    void loop() {
      while(stopPin != false){
          digitalWrite(8, HIGH);
          logfile.print(millis()); logfile.print(", "); logfile.println(analogRead(0));
          Serial.print(millis()); Serial.print(", "); Serial.println(analogRead(0));
          digitalWrite(8, LOW);
          stopPin = digitalRead(switchPin);
          delay(100);
      }
      logfile.flush();
      error(5); // flash 5 times to indicate stop condition

    }