Added info about tags in default branch.

+ Added 600ms pause before spin numbers if button pressed
* Changed increment delay 500ms -> 200ms
* Button bounce compensation code

.hgignore

@@ -0,0 +1,6 @@
+^\.vscode
+\.swp$
+\.bak$
+\.old$
+\.orig$
+\.clang-format

.hgtags

@@ -0,0 +1,3 @@
+ee4999ebdd2d1b54512facafdd03c8a530ea4bfa v1.0
+1167bd4b622768ed17e116a4cbac3db90031e6f8 v1.1
+109112211e454e608911949914eaa2722fbfed7d v1.2

README.md

@@ -4,13 +4,32 @@
 
 ### Component base is very simple:
 
-* Arduino NANO v3 chinese replica
-* 7 segment 4 digit LED indicator with common anode, FYQ-5641BG-21
+* Arduino NANO v3 chinese replica (on Atmega-168 chip)
+* 7 segment 4 digit LED indicator with common anode, FYQ-5641BD-21 (red LEDs)
 * 8 resistors that limiting current on LED segments, 330 Ohms, 0.25 watts
-* RTC Module GEEGROW with DS1307 chip
+* RTC Module GEEGROW with DS1307 chip (very basic, only RTC chip, quartz resonator, button battery, no additional memory chip)
 * 5x7 cm single side prototyping board
 * usb phone charger as power supply
 * 2 push buttons
 * 1 on/off switch
 * Gainta G521G enclosure (92x66.5x28мм)
 * 5m power cord
+
+### Optionally you may need:
+
+* Capasitor with well capacity if your charger has small capasitor on output
+* Fuse, to protect your device
+* DC/DC transformer if you have power supply that gives more than 5 volts or less than 4.5 volts (this will give additional surge protection if your power supply dies, this can happen after 3-5 years of uninterrupted work)
+
+### Additional Notes:
+
+My RTC module is not very accurate due to bad quartz chrystal calibration, looks like it is not exactly 32768 Hz and clock runs faster than it should be, giving about 5-8 seconds runaway per day. So i have to implement time correction in software (temperature changes during day/month/year is not very big - about 10 degrees Celsius, so we can use software compensation without thermal compensation).
+
+This project split into 2 branches:
+
+* **default** that contains generic clock without any additional elements
+* **photoresistor** that contains additional hardware - photocell bridge - and software algorithm that compensates ambient light sensed by photocell basing on LED display charachteristics.
+
+### Stable tags for branches:
+v1.5 - default
+v1.4 - photoresistor

simpleclock.ino

@@ -1,137 +1,170 @@
-/*  
- *           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;
-
-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 = true;          
-
-	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();
-
-	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();
-
-	// make blinking dot
-	if (dot == true) {
-		Display.setNumber((clock.hour * 100 + clock.minute), 2);
-	} else {
-		Display.setNumber((clock.hour * 100 + clock.minute));
-	}
-
-	Display.refreshDisplay();
-}
-
-/* vim: set filetype=cpp: */
+/*
+ * 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.
+ */
+
+/* DS1307 lib by FrankieChu for Seeed RTC module, in my case
+ * Grove___RTC_DS1307-1.0.0.zip */
+#include <DS1307.h>
+#include <SevSeg.h>
+
+DS1307 clock;
+SevSeg Display;
+
+/* push button stuff */
+const long initial_delay = 600;   // wait a bit before spin numbers
+const long adjust_interval = 200; // delay between consecutive number increments
+const long bounce_delay = 20;     // contact bounce compensation
+const int hrs_btn = A0;           // put hour adjusting button on A0 lane
+const int min_btn = A1;           // put minute adjusting button on A1 lane
+bool btn_pushed = false;          // is button pushed?
+unsigned long currentPushTimer;
+unsigned long previousPushTimer = 0;
+uint8_t minutes;
+uint8_t hours;
+
+/* dot blinking stuff */
+unsigned long currentMillis;
+unsigned long previousMillis = 0;
+const long interval = 500;
+bool dot = true;
+
+/* time inaccuracy compensation flag */
+bool compflag = true;
+
+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(100);
+
+	// 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 2019
+		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()
+{
+	currentMillis = millis();
+	currentPushTimer = currentMillis;
+	char str[4];
+	float d;
+
+	clock.getTime();
+
+	// push button magic
+	if ((!btn_pushed) and
+	    ((digitalRead(hrs_btn) == LOW) or (digitalRead(min_btn) == LOW))) {
+		if (currentPushTimer - previousPushTimer >= initial_delay) {
+			previousPushTimer = currentPushTimer;
+			btn_pushed = true;
+		}
+	}
+
+	if (btn_pushed and
+	    (digitalRead(hrs_btn) != LOW) and (digitalRead(min_btn) != LOW)) {
+		// compensate possible contact bounce with delay
+		if (currentPushTimer - previousPushTimer >= bounce_delay) {
+			btn_pushed = false;
+		}
+	}
+
+	if (btn_pushed) {
+		if (currentPushTimer - previousPushTimer >= adjust_interval) {
+			previousPushTimer = currentPushTimer;
+
+			if (digitalRead(hrs_btn) == LOW) {
+				hours = clock.hour + 1;
+				(hours > 23) ? hours = 0 : hours;
+				clock.fillByHMS(hours, clock.minute, 0);
+				clock.setTime();
+			}
+
+			if (digitalRead(min_btn) == LOW) {
+				minutes = clock.minute + 1;
+				(minutes > 59) ? minutes = 0 : minutes;
+				clock.fillByHMS(clock.hour, minutes, 0);
+				clock.setTime();
+			}
+		}
+	}
+
+	if (currentMillis - previousMillis >= interval) {
+		previousMillis = currentMillis;
+
+		if (dot)
+			dot = false;
+		else
+			dot = true;
+	}
+
+	/*
+	 * 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
+	 * shielding?
+	 */
+
+	if ((clock.hour == 21) and (clock.minute == 21) and
+	    (clock.second == 21) and (compflag)) {
+		clock.fillByHMS(clock.hour, clock.minute, 14);
+		clock.setTime();
+		compflag = false;
+	}
+
+	if ((clock.hour == 21) and (clock.minute == 21) and
+	    (clock.second == 23) and (!compflag)) {
+		compflag = true;
+	}
+
+	// make blinking dot
+	if (clock.hour > 0) {
+		if (dot) {
+			Display.setNumber((clock.hour * 100 + clock.minute), 2);
+		} else {
+			Display.setNumber((clock.hour * 100 + clock.minute));
+		}
+	} else {
+		/* 0 o'clock is an exception, we don't want to see "00.00", we
+		   want see "0.00" or "0 00", so we have to use this "hack" */
+		if (dot) {
+			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: */