simpleclock/simpleclock.ino

/*  
 *           7 Segment 4 Digits clock with digit point separator
 *  
 *           It uses display module with common anode and DS1307
 *           RTC module to enhance time keeping ability of
 *           Atmega 328p based Arduino nano microcontroller and
 *           2 buttons for adjusting time.
 */

/* This software distributed under BSD 2 Clause License

Copyright (c) Sergei Fedosoff, All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list
of conditions and the following disclaimer. Redistributions in binary form must
reproduce the above copyright notice, this list of conditions and the following
disclaimer in the documentation and/or other materials provided with the
distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
OF SUCH DAMAGE.
*/

#include <SevSeg.h>
#include <Wire.h>
#include <TimeLib.h>
// DS1307 lib by FrankieChu for Seeed RTC module
#include <DS1307.h>

DS1307 clock;
SevSeg Display;

unsigned long currentMillis;
unsigned long previousMillis = 0;
const long interval = 500;
const int hrs_btn = A0;
const int min_btn = A1;
bool dot = true;
uint8_t minutes;
uint8_t hours;
/* time inaccuracy compensation flag */
uint8_t compflag = 0;

void setup()
{
	// setup display
	byte hardwareConfig = COMMON_ANODE;
	byte numDigits = 4;
	byte digitPins[] = {9, 10, 11, 12};
	byte segmentPins[] = {2, 3, 4, 5, 6, 7, 8, 13};
	bool resistorsOnSegments = true;   // 8 resistors, 330 Ohms each
	bool updateWithDelays = false;     // Default. Recommended
	/* without it there is visual bug at 0 o'clock, and in current version of
	 * SevSeg' setChars() does not dots at all */
	bool leadingZeros = false;          

	Display.begin(hardwareConfig, numDigits, digitPins, segmentPins,
                      resistorsOnSegments, updateWithDelays, leadingZeros);
	Display.setBrightness(90);

	// setup clock
	clock.begin();

	// if rtc returns incorrect time, reset it to some default value
	clock.getTime();

	if (( clock.hour > 23 ) || (clock.minute > 59))
	{
		clock.fillByYMD(2019,2,23);  // 23 Feb 2013
		clock.fillByHMS(15,52,30);   // 15:52 30"
		clock.fillDayOfWeek(SAT);    // Saturday
		clock.setTime();             // put date to rtc
	}

	// setup control buttons
	pinMode(hrs_btn, INPUT_PULLUP);
	pinMode(min_btn, INPUT_PULLUP);
}


void loop()
{
	unsigned long currentMillis = millis();
	char str[4];
	float d;
	
	if (currentMillis - previousMillis >= interval)
	{
		previousMillis = currentMillis;

		if (dot == false)
		{
			dot = true;

			if (digitalRead(hrs_btn) == LOW)
			{
				clock.getTime();
				hours = clock.hour + 1;
				(hours > 23)? hours = 0: hours;
				clock.fillByHMS(hours, clock.minute, 0);
				clock.setTime();
			}

			if (digitalRead(min_btn) == LOW)
			{
				clock.getTime();
				minutes = clock.minute + 1;
				(minutes > 59)? minutes = 0: minutes;
				clock.fillByHMS(clock.hour, minutes, 0);
				clock.setTime();
			}
		}
		else
		{
			dot = false;
		}
	}

	clock.getTime();
  /*
   * Let's implement time compenstion for individual rtc module time
   * charachteristics. In in my case quartz resonator as inaccurate as
   * +/- about 5-8 seconds per 24 hours, maybe its require more EMI
   * sheilding?
   */

	if ((clock.hour == 21) and (clock.minute == 21) and (clock.second == 21) and (compflag == 0)) {
		clock.second = 14;
		clock.fillByHMS(clock.hour,clock.minute,clock.second);
		clock.setTime();
		compflag = 1;
	}

	if ((clock.hour == 21) and (clock.minute == 21) and (clock.second == 23) and (compflag == 1)) {
		compflag = 0;
	}

	// make blinking dot
	if (clock.hour > 0)
	{
		if (dot == true) 
		{
			Display.setNumber((clock.hour * 100 + clock.minute), 2);
		}
		else
		{
			Display.setNumber((clock.hour * 100 + clock.minute));
		}
	}
	else
	{
		/* 0 o'clock is an exception, we dont want to see "00.00", we want see
		 * "0.00" or "0 00", so we have to use this "hack" */
		if (dot == true)
		{
			d = float(clock.minute) / 100;
			Display.setNumber(d, 2);
		}
		else
		{
			sprintf(str, "%2d%02d", clock.hour, clock.minute);
			Display.setChars(str);
		}
	}

	Display.refreshDisplay();
}

/* vim: set filetype=cpp: */