This is a port of the Adafruit driver and DateTime library for the DS1307 RTC controller

Dependents:   espresso-machine-control SAT_OLED Mbedesclava Mbedmaestra ... more

You are viewing an older revision! See the latest version

Homepage

Table of Contents

  1. RTCLib
  2. Example

RTCLib

This was ported from Adafruit's RTCLib

Example

Note

I haven't yet tried to compile this example code.

It should be ok, as most of it (98%) was taken from a working project.

#include "mbed.h"
#include "DS1307.h"

class I2C2 : public I2C
{
public:
    I2C2 ( PinName sda, PinName scl, int hz, const char *name = NULL) : I2C ( sda, scl, name) { frequency(hz * 100); };
};

I2C2 gI2c ( p28, p27, 100 );
RtsDs1307 gRtc ( gI2c );
Serial gSerial(USBTX, USBRX);

void printDT(char *pre, DateTime &dt)
{
    gSerial.printf("%s - %u/%u/%02u %2u:%02u:%02u\r\n"
                ,pre
                ,dt.month(),dt.day(),dt.year()
                ,dt.hour(),dt.minute(),dt.second()
                );
}

bool rtcUpdate(RtcDs1307 &rtc, int32_t bias) // this must be signed
{   bool bUpdated = false;

    // Use the compiled date/time as a basis for setting the clock.
    // We assign it to a signed integer so that negative biases work correctly
    int64_t compiledTime = DateTime(__DATE__,__TIME__).unixtime();

    // This assumes that the program is run VERY soon after the initial compile.
    time_t localt = DateTime(compiledTime + bias).unixtime(); // offset by bias
    
    // If the stored static time stamp does not equal the compiled time stamp,
    // then we need to update the RTC clock and the stored time stamp
    if(*((time_t *)&rtc[0]) != localt)
    {
        // Update the RTC time as local time, not GMT/UTC
        rtc.adjust(localt);
        // Store the new compiled time statically in the object ram image
        *((time_t *)&rtc[0]) = localt;
        // Push the object ram image to the RTC ram image
        bUpdated = rtc.commit();
    }
    
    return bUpdated;
}

int main()
{   time_t tick = 0;

    if(rtcUpdate(gRtc, -(5*60*60) )) // CDT
        gSerial.printf("Updated RTC to compiled time\r\n");
    gSerial.printf("compiled %s %s\r\n",__DATE__,__TIME__);
    DateTime timeFlashed(*((time_t *)&gRtc[0]));
    printDT("last flashed on",timeFlashed);
    DateTime dt = gRtc.now();
    printDT("reset",dt);

    gSerial.printf("rtc clock is %s\r\n", (gRtc.isRunning() ? "running" : "halted");

    while(1)
    {
        if(time(NULL) >= tick)
        {
            DateTime dt = gRrtc.now();
            gSerial.printf("%u/%u/%02u %2u:%02u:%02u          \r"
                ,dt.month(),dt.day(),dt.year()
                ,dt.hour(),dt.minute(),dt.second()
                );
            tick = time(NULL)+1;
        }
    }
}



All wikipages