 
 void enterSleep()
 {
+  power_usart0_disable();// Serial (USART) 
+
   sleep_enable();
 
   attachInterrupt(0, pinInterrupt, RISING);

    pinMode(i, INPUT_PULLUP);     
  }
  ADCSRA = 0;  // disable ADC as we won't be using it

  Serial.begin(9600);
  Serial.println(F("Starting up..."));


int logData() {
  String year, month, day, hour, minute, second;
  power_twi_enable();
  power_spi_enable();

  DateTime datetime = RTC.now();
  year = String(datetime.year(), DEC);
  month = String(datetime.month(), DEC);
