coding suhu arduino

#include <SD.h>

#include <SPI.h>

#include <DS3231.h>

File data_file;

DS3231  rtc(SDA, SCL);




const int lm35_pin = A0; 

int temperature;  

int chip_select_pin = 10;     //pin 53 for arduino mega 2560




void setup() {

  Serial.begin(9600);

  rtc.begin();  

  pinMode(lm35_pin, INPUT);

  pinMode(chip_select_pin, OUTPUT);

  if (SD.begin())

  {

    Serial.println("Initialization Successful. Ready to use");

  } else

  {

    Serial.println("Initialization failed. Check your pin connections or change your SD card");

    return;

  }

    

}




void loop() {

  temperature = analogRead(lm35_pin);

  temperature = (temperature*500)/1023;

  data_file = SD.open("test.txt", FILE_WRITE);

  if (data_file) {    

    Serial.print(rtc.getTimeStr());

    data_file.print(rtc.getTimeStr());

    Serial.print(",");

    data_file.print(",");    

    Serial.println(temperature);

    data_file.println(temperature);

    data_file.close();

  }

  

  else {

    Serial.println("error opening your SD card file. Try again");

  }

  delay(3000);

}