Real Time Clock¶

Micro Crystal RV-3028-C7 RTC

Datasheets

Description¶

The RV-3028-C7 is a SMT Real-Time Clock Module that incorporates an integrated CMOS circuit together with an XTAL.

Extreme low power consumption: 45 nA @ 3 V.

Usage¶

The example below shows how to set a new time. If the time is once set correctly, there is a backup battery which provides the rtc alway with the needed power.

struct tm setTime = { 0 };
// Fill up the tm struct for 24 / 05 / 2021 (Monday)
setTime.tm_year = 121;      // Years since 1900
setTime.tm_mon = 4;         // Months since january
setTime.tm_mday = 24;       // Day of the month
setTime.tm_hour = 10;       // Hour
setTime.tm_min = 30;        // Minutes
setTime.tm_sec = 00;        // Seconds
setTime.tm_wday = 1;        // Days since sunday

// Send the new time to the rtc
yggdrasil_RealTimeClock_SetTime(mktime(&setTime));

tm setTime = { 0 };
// Fill up the tm struct for 24 / 05 / 2021 (Monday)
setTime.tm_year = 121;      // Years since 1900
setTime.tm_mon = 4;         // Months since january
setTime.tm_mday = 24;       // Day of the month
setTime.tm_hour = 10;       // Hour
setTime.tm_min = 30;        // Minutes
setTime.tm_sec = 00;        // Seconds
setTime.tm_wday = 1;        // Days since sunday

// Send the new time to the rtc
bsp::ygg::prph::RealTimeClock::setTime(mktime(&setTime));

To read the time from the rtc, this example shows how.

time_t time = yggdrasil_RealTimeClock_GetTime();

time_t time =  bsp::ygg::prph::RealTimeClock::getTime();

When the time should be printed, the example below shows an easy way.

char buffer[0xFF] = { 0 };
struct tm * time;

// Read the time as a time_t
time_t rtcTime = yggdrasil_RealTimeClock_GetTime();

// Transform to a tm struct
time = gmtime(&rtcTime);
// Get the time formatted
strftime(buffer, sizeof(buffer), "%c", time);
printf("Time: %s \n", buffer);

std::string buffer(0xFF, 0x00);
tm * time;

// Read the time as a time_t
time_t rtcTime = bsp::ygg::prph::RealTimeClock::getTime();

// Transform to a tm struct
time = gmtime(&rtcTime);
// Get the time formatted
strftime(buffer.data(), buffer.size(), "%c", time);
printf("Time: %s \n", buffer.data());