Real-Time Clock and Calendar API¶

MCP79412RTC Repo, BoxLambda fork, boxlambda branch: https://github.com/epsilon537/MCP79412RTC
MCP79412RTC Submodule in the BoxLambda Directory Tree: sub/MCP79412RTC/.
RTCC Software Component in the BoxLambda Directory Tree: sw/components/rtcc
Included in OS: No

The Real-Time Clock and Calendar (RTCC) software component is based on the MCP79412RTC library. The library interfaces with Digilent's PMOD RTCC via I2C.

The library allows you to set and get a time and date (among other things). The RTCC's coin cell battery backup ensures that the time and date will be maintained while the host (BoxLambda) is turned off.

Example usage:

  /*Time elements structure*/
  tmElements_t tmElements;

  RTC.begin();

  if (RTC.isRunning()) {
    printf("RTC oscillator is already running.\n");
  }
  else {
    printf("RTC oscillator is not running yet. Enabling...\n");

    RTC.vbaten(true);

    /*Some bogus initial values.*/
    tmElements.Second = 1;
    tmElements.Minute = 2;
    tmElements.Hour = 3;
    tmElements.Wday = 4;   // day of week, sunday is day 1
    tmElements.Day = 5;
    tmElements.Month = 6;
    tmElements.Year = 7;   // offset from 1970;

    RTC.write(tmElements);
  }

  uint8_t prevSecond = 0;

  for (;;) {
    RTC.read(tmElements);

    /*print a line when the seconds change.*/
    if (tmElements.Second != prevSecond) {
      prevSecond = tmElements.Second;

      printf("sec: 0x%x, min: 0x%x, hour: 0x%x.\n", (unsigned)tmElements.Second, (unsigned)tmElements.Minute, (unsigned)tmElements.Hour);
    }
  }

For additional example code, check the rtcc_test app: