Workflow

system_init();

struct rtc_calendar_time time;
rtc_calendar_get_time_defaults(&time);
time.year   = 2012;
time.month  = 12;
time.day    = 31;
time.hour   = 23;
time.minute = 59;
time.second = 59;

configure_rtc_calendar();

1. 3.1.
   Create a RTC configuration structure to hold the desired RTC driver settings and fill it with the default driver configuration values.

   struct rtc_calendar_config config_rtc_calendar;
   rtc_calendar_get_config_defaults(&config_rtc_calendar);
   

   Note: This should always be performed before using the configuration struct to ensure that all values are initialized to known default settings.
2. 3.2.
   Create and initialize an alarm.

   alarm.time.year      = 2013;
   alarm.time.month     = 1;
   alarm.time.day       = 1;
   alarm.time.hour      = 0;
   alarm.time.minute    = 0;
   alarm.time.second    = 4;
   

3. 3.3.
   Change settings in the configuration and set alarm.

   config_rtc_calendar.clock_24h = true;
   config_rtc_calendar.alarm[0].time = alarm.time;
   config_rtc_calendar.alarm[0].mask = RTC_CALENDAR_ALARM_MASK_YEAR;
   

4. 3.4.
   Initialize the module with the set configurations.

   rtc_calendar_init(&rtc_instance, RTC, &config_rtc_calendar);
   

5. 3.5.
   Enable the module.

   rtc_calendar_enable(&rtc_instance);
   

configure_rtc_callbacks();

1. 4.1.
   Register overflow callback.

   rtc_calendar_register_callback(
           &rtc_instance, rtc_match_callback, RTC_CALENDAR_CALLBACK_ALARM_0);
   

2. 4.2.
   Enable overflow callback.

   rtc_calendar_enable_callback(&rtc_instance, RTC_CALENDAR_CALLBACK_ALARM_0);
   

rtc_calendar_set_time(&rtc_instance, &time);