/*----------------------------------------------------------------------*

* Displays the date and time from an MCP79412 RTC every second. *

* *

* Set the date and time by entering the following on the Arduino *

* serial monitor: *

* Syear,month,day,hour,minute,second, *

* *

* Where *

* year can be two or four digits, *

* month is 1-12, *

* day is 1-31, *

* hour is 0-23, and *

* minute and second are 0-59. *

* *

* Set the calibration register by entering the following: *

* Cnnn, *

* *

* Where nnn can be a positive or negative value, e.g. "c4" or "c-42". *

* *

* Entering the final comma delimiter (after "second") will avoid a *

* one-second timeout and will allow the RTC to be set more accurately. *

* *

* No validity checking is done, invalid values or incomplete syntax *

* in the input will result in an incorrect RTC setting. *

* *

* Jack Christensen 28Aug2013 *

* *

* Tested with Arduino 1.0.5, Arduino Uno. *

* *

* This work is licensed under the Creative Commons Attribution- *

* ShareAlike 3.0 Unported License. To view a copy of this license, *

* visit http://creativecommons.org/licenses/by-sa/3.0/ or send a *

* letter to Creative Commons, 171 Second Street, Suite 300, *

* San Francisco, California, 94105, USA. *

*----------------------------------------------------------------------*/

#include <MCP79412RTC.h> //http://github.com/JChristensen/MCP79412RTC

#include <Streaming.h> //http://arduiniana.org/libraries/streaming/

#include <Time.h> //http://playground.arduino.cc/Code/Time

#include <Wire.h> //http://arduino.cc/en/Reference/Wire

void setup(void)

{

byte rtcID[8];

Serial.begin(115200);

//setSyncProvider() causes the Time library to synchronize with the

//external RTC by calling RTC.get() every five minutes by default.

setSyncProvider(RTC.get);

Serial << endl << F("RTC Sync");

if (timeStatus() != timeSet) Serial << F(" FAIL!");

Serial << endl;

RTC.idRead(rtcID);

Serial << F("RTC ID = ");

for (int i=0; i<8; ++i) {

if (rtcID[i] < 16) Serial << '0';

Serial << _HEX(rtcID[i]);

}

Serial << endl;

RTC.getEUI64(rtcID);

Serial << F("EUI-64 = ");

for (int i=0; i<8; ++i) {

if (rtcID[i] < 16) Serial << '0';

Serial << _HEX(rtcID[i]);

}

Serial << endl;

Serial << F("Calibration Register = ") << RTC.calibRead() << endl;

}

void loop(void)

{

static time_t tLast;

time_t t;

tmElements_t tm;

int cmdChar, y, oldCal, newCal;

//check for input, first character is a command, "S" to set date/time, or "C" to set the calibration register

if (Serial.available()) {

cmdChar = Serial.read();

switch (cmdChar) {

case 'S':

case 's':

//note that the tmElements_t Year member is an offset from 1970,

//but the RTC wants the last two digits of the calendar year.

//use the convenience macros from Time.h to do the conversions.

y = Serial.parseInt();

if (y >= 100 && y < 1000)

Serial << F("Error: Year must be two digits or four digits!") << endl;

else {

if (y >= 1000)

tm.Year = CalendarYrToTm(y);

else //(y < 100)

tm.Year = y2kYearToTm(y);

tm.Month = Serial.parseInt();

tm.Day = Serial.parseInt();

tm.Hour = Serial.parseInt();

tm.Minute = Serial.parseInt();

tm.Second = Serial.parseInt();

t = makeTime(tm);

RTC.set(t); //use the time_t value to ensure correct weekday is set

setTime(t);

Serial << F("RTC set to: ");

printDateTime(t);

Serial << endl;

}

break;

case 'C':

case 'c':

newCal = Serial.parseInt();

oldCal = RTC.calibRead();

RTC.calibWrite(newCal);

Serial << F("Calibration changed from ") << oldCal << F(" to ") << RTC.calibRead() << endl;

break;

default:

Serial << endl << F("Unrecognized command: ") << (char)cmdChar << endl;

break;

}

//dump any extraneous input

while (Serial.available() > 0) Serial.read();

}

t = now();

if (t != tLast) {

tLast = t;

printDateTime(t);

Serial << endl;

}

}

//print date and time to Serial

void printDateTime(time_t t)

{

printDate(t);

Serial << ' ';

printTime(t);

}

//print time to Serial

void printTime(time_t t)

{

printI00(hour(t), ':');

printI00(minute(t), ':');

printI00(second(t), ' ');

}

//print date to Serial

void printDate(time_t t)

{

printI00(day(t), 0);

Serial << monthShortStr(month(t)) << _DEC(year(t));

}

//Print an integer in "00" format (with leading zero),

//followed by a delimiter character to Serial.

//Input value assumed to be between 0 and 99.

void printI00(int val, char delim)

{

if (val < 10) Serial << '0';

Serial << _DEC(val);

if (delim > 0) Serial << delim;

return;

}