     reg += 1;
   }
   Serial.println();
+
+  if(seconds >= 128)
+  {
+    Serial.println(F("/!\\ WARNING: RTC oscillator frozen. Recommend reset.\n"));
+  }
 
   seconds  = (seconds & 0x0F)  + ((seconds >> 4) * 10);
   minutes  = (minutes & 0x0F)  + ((minutes >> 4) * 10);

char *months     = 0;
byte years       = 0;

void setup()
{
  // put your setup code here, to run once:
  Wire.begin();
  Serial.begin(9600);
  while(!Serial);
  
  Serial.println(F("PCF8523 Registers:"));
  Wire.beginTransmission(deviceAddr);

void loop()
{  
  // put your main code here, to run repeatedly:
  while(1)
  {
    if(FLAG)
    {
      digitalWrite(7, LOW);
      FLAG = false;
      Wire.beginTransmission(deviceAddr);
      Wire.write(reg_Control_2);
      Wire.write(byte(0x02));
      Wire.endTransmission();
      digitalWrite(7, HIGH);
    }
  }
}

void INT1_ISR()                 // Serial On Button ISR. Activate Serial Interface
{
  FLAG = true;
}
