MINUTES_SECONDS_MATCH -> alarm when minutes and seconds match SECONDS_MATCH -> alarm when seconds match Void Alarm1_Set(RTC_Time *time_t, al1 _config): sets alarm1 of the DS3231 where the variable time_t of type struct and _config is alarm1 configuration which should be one of the following: RTC_Time *RTC_Get(): reads time and date from the DS3231, this function returns them as a variable of type struct (same as the previous function). Where dow is day of the week (Monday, Tuesday …) and day is month day.ĭow range: 1 – 7 (1 equals Sunday, 2 equals Monday …) Seconds, minutes, hours, dow, day, month and year.

Void RTC_Set(RTC_Time *time_t): this function sets time and date (writes time and date to the DS3231) where the variable time_t of type struct (structure) collects the following integer variables: The following image shows a typical operating circuit of the DS3231:ĭS3231 RTC driver (library) for CCS C compiler: The date at the end of the month is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The DS3231 RTC maintains seconds, minutes, hours, day, date, month, and year information. The integration of the crystal resonator enhances the long-term accuracy of the device as well as reduces the piece-part count in a manufacturing line. The device incorporates a battery input, and maintains accurate timekeeping when main power to the device is interrupted.

The DS3231 is a low-cost, extremely accurate I2C real-time clock (RTC) with an integrated temperature compensated crystal oscillator (TCXO) and crystal. General Description (from the DS3231 datasheet):

The compiler used in this example is CCS C. This topic shows how to make a simple real time clock using DS3231 and PIC16F877A microcontroller where time and date are displayed on 20×4 LCD screen.

Rtc ic ds3231 wire library