Código para funcionamento do cartão

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

const int chipSelect = 4;
const int LM35 =A0;
float temp = 0;
int lido = 0;
int t = 0 ;


void setup() {
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }


  Serial.print("inicializando cartão");

  // see if the card is present and can be initialized:
  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present");
    // don't do anything more:
    while (1);
  }
  Serial.println("card initialized.");
}

void loop()
{
  temp = (float(analogRead(LM35))*5/(1023))/0.01;{
  // make a string for assembling the data to log:
  String dataString = "";

  // read three sensors and append to the string:
  for (int analogPin = 0; analogPin < 1; analogPin++) {
    int sensor = analogRead(analogPin);
    dataString += String(sensor);
    if (analogPin < 2) {
      dataString += ",";
    }
  }

  // open the file. note that only one file can be open at a time,
  // so you have to close this one before opening another.
  File dataFile = SD.open("datalog1.txt", FILE_WRITE);

  // if the file is available, write to it:
  if (dataFile) {
    Serial.print("tempo: ");
    Serial.print(t);
    Serial.print("     Temperatura:  ");
Serial.println(temp);
t=t+2;

    dataFile.println(temp);
    dataFile.println(t);
    dataFile.close();
    // print to the serial port too:
    Serial.println(temp);
  }
  // if the file isn't open, pop up an error:
  else {
    Serial.println("error opening datalog.txt");
  }
  }
delay(2000);
}