pinSquareWave()

This function sets the "INT/SQW" pin on the DS3231M to output a 1Hz square wave. This disables the setting of pinAlarm(). {Update Version 1.0.7} This function now accepts an optional parameter, "rate". If not used it works as before, setting a 1Hz square wave output on both the DS3231M and the DS3231 chips. If the "rate" is specified for the DS3231M it always sets a 1Hz signal, but on the DS3231 it will set the output to the following values:

Value	Rate
0	1Hz
1	1.024kHz
2	2.048kHz
3	4.096kHz

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Example:

...
DS3231M_Class DS3231M; // Create an instance of the DS3231M
...
void setup() {
  Serial.begin(SERIAL_SPEED);
  while (!DS3231M.begin()) { // Initialize RTC communications
    Serial.println("Unable to find DS3231M. Checking again in 1 second.");
    delay(1000);
  } // of loop until device is located
 uint8_t alarmType;
 DS3231M.pinSquareWave();
 DS3231M.setAlarm(secondsMinutesHoursDateMatch,DateTime(2017,8,5,18,30,0)); // 18:30:00 on 2017-08-05
 while (!DS3231M.isAlarm()); // loop until the alarm is triggered
 DS3231M.clearAlarm(); // Turn off the alarm
...