DS1337: I²C Real time clock form Dallas Maxim

Usage Example

This is not a full documentation, which will come later, but it should be enough to get you started.

void setup()
{
	// Set the clock using a unix time stamp (date -u +'%s')
	RTC.clockSet(1192390068); //Sun Oct 14 15:27:48 EDT 2007
	
	// Setup a callback function for the integrity check
	// See below for the callback functions
	RTC.clockIntegrityCallback(integrityCallback);
	
	// Enable the Square Wave @ 1Hz on INTB
	RTC.sqwSetRate(DS1337_SQW_1HZ);
	RTC.sqwEnable();
	
	// Setup the first alarm
	RTC.alarmSelect(0); // Switch to alarm 2
	RTC.alarmSet(RTC_SEC,	30);
	RTC.alarmSet(RTC_MIN,	18);
	RTC.alarmSet(RTC_HR,	0);
	RTC.alarmSet(RTC_DOW,	0);
	
	// Match mode: every minutes and seconds
	RTC.alarmSet(DS1337_ALARM_MODE, DS1337_ALARM_MCH_MINSEC);
	
	// Setup callback function for alarm 1
	RTC.alarmSetCallback(alarmCallback1);
	
	// Setuo the external interrupt on INTA for alarm1
	RTC.alarmSetInterrupt();
	
	RTC.alarmSelect(1); // Switch to alarm 2
	
	// Match mode: once per minute at 00s
	RTC.alarmSet(DS1337_ALARM_MODE, DS1337_ALARM_PER_MIN);
	
	// Setup callback function for alarm 2
	RTC.alarmSetCallback(alarmCallback2);
	
	// Setup the interrupt for alarm 2
	// If the square wave is enabled, it will output on INTA
	// if the SQW is disabled the interrupt will happen on INTB
	RTC.alarmSetInterrupt();
}

void loop()
{
	RTC.clockChecks(); // Performs alarm and integrity checks for call back functions
}

// Note that the alarm registers will stay high
// until these function are finished executing.
void alarmCallback1(void)
{
	Serial.print("alarm 1 triggerd");
	return;
}
void alarmCallback2(void)
{
	Serial.print("alarm 2 triggerd");
	return;
}

void integrityCallback(void)
{
	Serial.print("Oscillator integrity fault!");
	
	// If the fault flag is high the clock is stopped
	// so in this function we can fix the time and start the clock again
	RTC.clockStart();
	return;
}