Will do that and report it later. However, the setA1Time does write hour/minute into the registers based on the following routines from the library:
void DS3231::setA1Time(byte A1Day, byte A1Hour, byte A1Minute, byte A1Second, byte AlarmBits, bool A1Dy, bool A1h12, bool A1PM) {
// Sets the alarm-1 date and time on the DS3231, using A1* information
byte temp_buffer;
Wire.beginTransmission(CLOCK_ADDRESS);
Wire.write(uint8_t(0x07)); // A1 starts at 07h
// Send A1 second and A1M1
Wire.write(decToBcd(A1Second) | ((AlarmBits & 0b00000001) << 7));
// Send A1 Minute and A1M2
Wire.write(decToBcd(A1Minute) | ((AlarmBits & 0b00000010) << 6));
// Figure out A1 hour
if (A1h12) {
// Start by converting existing time to h12 if it was given in 24h.
if (A1Hour > 12) {
// well, then, this obviously isn't a h12 time, is it?
A1Hour = A1Hour - 12;
A1PM = true;
}
if (A1PM) {
// Afternoon
// Convert the hour to BCD and add appropriate flags.
temp_buffer = decToBcd(A1Hour) | 0b01100000;
} else {
// Morning
// Convert the hour to BCD and add appropriate flags.
temp_buffer = decToBcd(A1Hour) | 0b01000000;
}
} else {
// Now for 24h
temp_buffer = decToBcd(A1Hour);
}
temp_buffer = temp_buffer | ((AlarmBits & 0b00000100)<<5);
// A1 hour is figured out, send it
Wire.write(temp_buffer);
// Figure out A1 day/date and A1M4
temp_buffer = ((AlarmBits & 0b00001000)<<4) | decToBcd(A1Day);
if (A1Dy) {
// Set A1 Day/Date flag (Otherwise it's zero)
temp_buffer = temp_buffer | 0b01000000;
}
Wire.write(temp_buffer);
// All done!
Wire.endTransmission();
}
void DS3231::setA2Time(byte A2Day, byte A2Hour, byte A2Minute, byte AlarmBits, bool A2Dy, bool A2h12, bool A2PM) {
// Sets the alarm-2 date and time on the DS3231, using A2* information
byte temp_buffer;
Wire.beginTransmission(CLOCK_ADDRESS);
Wire.write(uint8_t(0x0b)); // A1 starts at 0bh
// Send A2 Minute and A2M2
Wire.write(decToBcd(A2Minute) | ((AlarmBits & 0b00010000) << 3));
// Figure out A2 hour
if (A2h12) {
// Start by converting existing time to h12 if it was given in 24h.
if (A2Hour > 12) {
// well, then, this obviously isn't a h12 time, is it?
A2Hour = A2Hour - 12;
A2PM = true;
}
if (A2PM) {
// Afternoon
// Convert the hour to BCD and add appropriate flags.
temp_buffer = decToBcd(A2Hour) | 0b01100000;
} else {
// Morning
// Convert the hour to BCD and add appropriate flags.
temp_buffer = decToBcd(A2Hour) | 0b01000000;
}
} else {
// Now for 24h
temp_buffer = decToBcd(A2Hour);
}
// add in A2M3 bit
temp_buffer = temp_buffer | ((AlarmBits & 0b00100000)<<2);
// A2 hour is figured out, send it
Wire.write(temp_buffer);
// Figure out A2 day/date and A2M4
temp_buffer = ((AlarmBits & 0b01000000)<<1) | decToBcd(A2Day);
if (A2Dy) {
// Set A2 Day/Date flag (Otherwise it's zero)
temp_buffer = temp_buffer | 0b01000000;
}
Wire.write(temp_buffer);
// All done!
Wire.endTransmission();
}
void DS3231::turnOnAlarm(byte Alarm) {
// turns on alarm number "Alarm". Defaults to 2 if Alarm is not 1.
byte temp_buffer = readControlByte(0);
// modify control byte
if (Alarm == 1) {
temp_buffer = temp_buffer | 0b00000101;
} else {
temp_buffer = temp_buffer | 0b00000110;
}
writeControlByte(temp_buffer, 0);
}
void DS3231::turnOffAlarm(byte Alarm) {
// turns off alarm number "Alarm". Defaults to 2 if Alarm is not 1.
// Leaves interrupt pin alone.
byte temp_buffer = readControlByte(0);
// modify control byte
if (Alarm == 1) {
temp_buffer = temp_buffer & 0b11111110;
} else {
temp_buffer = temp_buffer & 0b11111101;
}
writeControlByte(temp_buffer, 0);
}