CRTC.cpp

#include "CRTC.h"

//TODO move into own header file

// CONNECTIONS:
// DS3231 SDA --> SDA
// DS3231 SCL --> SCL
// DS3231 VCC --> 3.3v or 5v
// DS3231 GND --> GND

//I2C pins
#define SDA 5 
#define SCL 4

CRTC::CRTC():
m_pSyncProvider(0),
syncInterval(86400),
nextSyncTime(0),
Rtc(Wire)
{
  
}

CRTC::~CRTC()
{
  
}

bool CRTC::setup()
{
  Wire.begin(SDA, SCL);

  Rtc.Begin();
  
  if (!Rtc.IsDateTimeValid()) 
  {
    Serial.println("CRTC::setup() - RTC lost confidence in the DateTime!");
    // This will most likely happen when the battery is low or the RTC is used the first time.
    // After setting the sync provider the time will be set correctly to utc
  }
  
  if (!Rtc.GetIsRunning())
  {
    Serial.println("CRTC::setup() - RTC was not actively running, starting now");
    Rtc.SetIsRunning(true);
  }
  
  Rtc.Enable32kHzPin(false);
  Rtc.SetSquareWavePin(DS3231SquareWavePin_ModeNone);
}


time_t CRTC::now()
{
	Serial.println("CRTC::now() - called");

	if (!Rtc.IsDateTimeValid()) 
	{
		// Common Cases:
		//    1) the battery on the device is low or even missing and the power line was disconnected
    Serial.println("CRTC::now() - RTC lost confidence in the DateTime! Trying to resync with SyncProvider");
		sync(0, true);
	}

	RtcDateTime now = Rtc.GetDateTime();
	time_t t((time_t)now.Epoch32Time());
	t = sync(t);

	return(t);
}

time_t CRTC::sync(time_t t, bool force)
{
	if(nextSyncTime <= (uint32_t)t || force == true)
	{
		if(0 != m_pSyncProvider)
		{
			Serial.println("CRTC::sync - resyncing");

			time_t tsync(m_pSyncProvider->now());
			if(0 != tsync)
			{
				setTime(tsync);
				t = tsync;
			}
			else
			{
				delay(1000);
				time_t tsync(m_pSyncProvider->now());
				if (0 != tsync)
				{
					setTime(tsync);
					t = tsync;
				}
				else
				{
					nextSyncTime = (uint32_t)t + syncInterval;
				}
			}
		}
	}

	return t;
}

void CRTC::setTime(time_t t)
{
	RtcDateTime now;
	now.InitWithEpoch32Time((uint32_t)t);
	Rtc.SetDateTime(now);
	nextSyncTime = (uint32_t)t + syncInterval;
}

void CRTC::setSyncProvider(ISyncProvider* pSyncProvider)
{
	m_pSyncProvider = pSyncProvider;  
	nextSyncTime = 0;
	now(); // this will sync the clock
}

// set the number of seconds between re-sync
void CRTC::setSyncInterval(time_t interval)
{
  
	syncInterval = (uint32_t)interval;
	RtcDateTime now = Rtc.GetDateTime();
	nextSyncTime = now.Epoch32Time() + syncInterval;
}