#include <Wire.h>
#include "RTClib.h"
#include <SD.h>
#include <SPI.h>

#define pinCS  10 				// Pin 10 auf Arduino Uno

RTC_DS1307 rtc;
File myFile;
int temperatur = 20;
DateTime now, last;
TimeSpan ts; 

void setup() {
    
	// init UART
  Serial.begin(9600);
  while (!Serial);

	// init RTC
  if (!rtc.begin()) {
    Serial.println("Couldn't find RTC!");
    while (1);
  }
  rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  Serial.println("RTC adjusted."); 
	last = rtc.now();
  
	// init SD card
  pinMode(pinCS, OUTPUT);  
  if (SD.begin()) {
    Serial.println("SD card is ready to use.");
  } else {
    Serial.println("SD card initialization failed!");
    while(1);
  }  
}

void loop() {

 	now = rtc.now();
  ts = now - last; 
  if (ts.totalseconds() >= 3600) {
		last = now;
 		String zeit = ((String) (now.year()) + (now.month()) + (now.day()) + (now.hour()));
 		String wetterdaten= (String) temperatur + "|Temperatur";
  	myFile = SD.open("test3.txt", O_WRITE | O_APPEND);
  	if (myFile) {
    	Serial.println("Writing to file...");    
      myFile.println(zeit+wetterdaten);
	    myFile.close(); 
  	  Serial.println("Done.");
    } else {
    	Serial.println("error opening test3.txt");
  	}
	}
  delay(1000);
}