Alarm time settings on a DS3231

Projects Programming
15

that's weird you have to add it yourself. it's included on line 23 of DS3231.h which you import in your code when you do

#include <DS3231.h>

and if you go check the library function code for getA1Time() that you call in the loop

void DS3231::getA1Time(byte& A1Day, byte& A1Hour, byte& A1Minute, byte& A1Second, byte& AlarmBits, bool& A1Dy, bool& A1h12, bool& A1PM) {
	byte temp_buffer;
	Wire.beginTransmission(CLOCK_ADDRESS);
	Wire.write(0x07);
	Wire.endTransmission();

	Wire.requestFrom(CLOCK_ADDRESS, 4);

	temp_buffer	= Wire.read();	// Get A1M1 and A1 Seconds
	A1Second	= bcdToDec(temp_buffer & 0b01111111);
	// put A1M1 bit in position 0 of DS3231_AlarmBits.
	AlarmBits	= AlarmBits | (temp_buffer & 0b10000000)>>7;

	temp_buffer		= Wire.read();	// Get A1M2 and A1 minutes
	A1Minute	= bcdToDec(temp_buffer & 0b01111111);
	// put A1M2 bit in position 1 of DS3231_AlarmBits.
	AlarmBits	= AlarmBits | (temp_buffer & 0b10000000)>>6;

	temp_buffer	= Wire.read();	// Get A1M3 and A1 Hour
	// put A1M3 bit in position 2 of DS3231_AlarmBits.
	AlarmBits	= AlarmBits | (temp_buffer & 0b10000000)>>5;
	// determine A1 12/24 mode
	A1h12		= temp_buffer & 0b01000000;
	if (A1h12) {
		A1PM	= temp_buffer & 0b00100000;			// determine am/pm
		A1Hour	= bcdToDec(temp_buffer & 0b00011111);	// 12-hour
	} else {
		A1Hour	= bcdToDec(temp_buffer & 0b00111111);	// 24-hour
	}

	temp_buffer	= Wire.read();	// Get A1M4 and A1 Day/Date
	// put A1M3 bit in position 3 of DS3231_AlarmBits.
	AlarmBits	= AlarmBits | (temp_buffer & 0b10000000)>>4;
	// determine A1 day or date flag
	A1Dy		= (temp_buffer & 0b01000000)>>6;
	if (A1Dy) {
		// alarm is by day of week, not date.
		A1Day	= bcdToDec(temp_buffer & 0b00001111);
	} else {
		// alarm is by date, not day of week.
		A1Day	= bcdToDec(temp_buffer & 0b00111111);
	}
}

you can see it uses the Wire library and calls all over the place as this is the way to communicate with the RTC module. check if you have the most recent library... So the whole thing would not work at all if Wire was not there in the first place...

but glad it works!