Added info about tags in default branch.

.gitignore

@@ -1,6 +0,0 @@
-.vscode/*
-*.swp
-*.bak
-*.old
-*.orig
-*.clang-format

.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

@@ -12,8 +12,6 @@
 * usb phone charger as power supply
 * 2 push buttons
 * 1 on/off switch
-* 1 photoresistor
-* 1 resistor to make secund shoulder of photosensitive "bridge", 10 kOhms, 0.25 watts
 * Gainta G521G enclosure (92x66.5x28мм)
 * 5m power cord
 
@@ -26,3 +24,12 @@
 ### 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

@@ -11,9 +11,6 @@
 #include <DS1307.h>
 #include <SevSeg.h>
 
-#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
-#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
-
 DS1307 clock;
 SevSeg Display;
 
@@ -23,32 +20,20 @@ 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
-volatile bool btn_pushed = false; // is button pushed?
+bool btn_pushed = false;          // is button pushed?
+unsigned long currentPushTimer;
 unsigned long previousPushTimer = 0;
+uint8_t minutes;
+uint8_t hours;
 
 /* dot blinking stuff */
-volatile bool dot = true;
+unsigned long currentMillis;
+unsigned long previousMillis = 0;
+const long interval = 500;
+bool dot = true;
 
 /* time inaccuracy compensation flag */
-volatile bool compflag1 = true;
+bool compflag = true;
-volatile bool compflag2 = false;
-const uint8_t timeSkew = 8;          // assume that clock runs faster than should
-volatile bool timeSkewEven = false;  // comp. 1 additional second per 2 days
-
-/* ambient light compensation aka night mode */
-const int photoPin = A2;
-volatile bool measureAmbLight = true;
-unsigned int ambLight = 0;
-unsigned long previousLightTimer = 0;
-const long refresh_interval = 40;    // refresh rate 25Hz
-
-/* time vars */
-volatile uint8_t mysecond;
-volatile uint8_t myminute;
-volatile uint8_t myhour;
-
-/* rtc sync flag */
-volatile bool rtcsync = true;
 
 void setup()
 {
@@ -58,12 +43,7 @@ void setup()
 	byte digitPins[] = {9, 10, 11, 12};
 	byte segmentPins[] = {2, 3, 4, 5, 6, 7, 8, 13};
 	bool resistorsOnSegments = true; // 8 resistors, 330 Ohms each
-	/* updateWithDelays defaults to false and it is recommended value,
+	bool updateWithDelays = false;   // Default. Recommended
-	 * but i was unable to make my display to change brightness notably with
-	 * recommended value, so i have to use updateWithDelays=true,
-	 * in this case brightness gets changed.
-	 */
-	bool updateWithDelays = true;
 
 	/* without it there is visual bug at 0 o'clock, and in current version
 	 * of SevSeg' setChars() does not dots at all */
@@ -89,96 +69,22 @@ void setup()
 	// setup control buttons
 	pinMode(hrs_btn, INPUT_PULLUP);
 	pinMode(min_btn, INPUT_PULLUP);
-
-/* Timer stuff
- * timer0 being used in millis() micros() delay() etc, it has 8 bit resolution
- * timer2 being used in analogWrite() tone() notone(), it has 8 bit resolution
- * timer1 being used in servo lib has 16 bit resolution
- * We'll use timer1, since we have no mechanical parts and don't need servo lib
- */
-	// initialize timer1
-	noInterrupts();           // disable all interrupts
-	TCCR1A = 0;
-	TCCR1B = 0;
-
-	TCNT1 = 34286;            // preload timer 65536-16MHz/256/2Hz
-	TCCR1B |= (1 << CS12);    // 256 prescaler 
-	TIMSK1 |= (1 << TOIE1);   // enable timer overflow interrupt
-	interrupts();             // enable all interrupts
-
-/* increase sampling rate of analogRead()
- * by setting an ADC prescale from 128 to 16, so it takes less time to read
- * sensor
- */
-	sbi(ADCSRA, ADPS2);
-	cbi(ADCSRA, ADPS1);
-	cbi(ADCSRA, ADPS0);
-
-	// setup ambient brigtness sensor
-	pinMode(photoPin, INPUT);
-	ambLight = analogRead(photoPin);
-}
-
-ISR(TIMER1_OVF_vect)
-{
-/* Feed clock twice per second */
-	TCNT1 = 34286;            // preload timer
-	// do not read rtc if time beng adjusted by buttons
-	(btn_pushed) ? rtcsync : rtcsync = true;
-
-/* Also switch dot */
-	if (dot)
-		dot = false;
-	else
-		dot = true;
-
-/* time compensation magic */
-	if ((myhour == 21) and (myminute == 21) and (mysecond == 21)
-	    and (compflag2)) {
-		compflag1 = true;
-		(timeSkewEven) ? timeSkewEven = false : timeSkewEven;
-	}
-
-	if ((myhour == 21) and (myminute == 21) and (mysecond == 23)) {
-		compflag1 = false;
-		compflag2 = true;
-	}
 }
 
 void loop()
 {
-	unsigned long currentMillis = millis();
+	currentMillis = millis();
+	currentPushTimer = currentMillis;
+	char str[4];
+	float d;
 
-/*
- * Let's implement time compenstion for individual rtc module time
- * charachteristics. In in my case quartz resonator as inaccurate as
- * about +8.5 seconds per 24 hours
- */
-	if (compflag1 && compflag2) {
-		if (timeSkewEven) {
-			clock.fillByHMS(myhour, myminute, (mysecond - timeSkew - 1));
-		} else {
-			clock.fillByHMS(myhour, myminute, (mysecond - timeSkew));
-		}
-
-		clock.setTime();
-		compflag2 = false;
-	}
-
-	if (rtcsync) {
 	clock.getTime();
-		mysecond = clock.second;
-		myminute = clock.minute;
-		myhour = clock.hour;
-		updateTimeStr(myhour, myminute);
-		rtcsync = false;
-	}
 
 	// push button magic
 	if ((!btn_pushed) and
 	    ((digitalRead(hrs_btn) == LOW) or (digitalRead(min_btn) == LOW))) {
-		if (currentMillis - previousPushTimer >= initial_delay) {
+		if (currentPushTimer - previousPushTimer >= initial_delay) {
-			previousPushTimer = currentMillis;
+			previousPushTimer = currentPushTimer;
 			btn_pushed = true;
 		}
 	}
@@ -186,93 +92,79 @@ void loop()
 	if (btn_pushed and
 	    (digitalRead(hrs_btn) != LOW) and (digitalRead(min_btn) != LOW)) {
 		// compensate possible contact bounce with delay
-		if (currentMillis - previousPushTimer >= bounce_delay) {
+		if (currentPushTimer - previousPushTimer >= bounce_delay) {
 			btn_pushed = false;
 		}
 	}
 
 	if (btn_pushed) {
-		if (currentMillis - previousPushTimer >= adjust_interval) {
+		if (currentPushTimer - previousPushTimer >= adjust_interval) {
-			previousPushTimer = currentMillis;
+			previousPushTimer = currentPushTimer;
 
 			if (digitalRead(hrs_btn) == LOW) {
-				myhour++;
+				hours = clock.hour + 1;
-				(myhour > 23) ? myhour = 0 : myhour;
+				(hours > 23) ? hours = 0 : hours;
-				clock.fillByHMS(myhour, myminute, 0);
+				clock.fillByHMS(hours, clock.minute, 0);
 				clock.setTime();
 			}
 
 			if (digitalRead(min_btn) == LOW) {
-				myminute++;
+				minutes = clock.minute + 1;
-				(myminute > 59) ? myminute = 0 : myminute;
+				(minutes > 59) ? minutes = 0 : minutes;
-				clock.fillByHMS(myhour, myminute, 0);
+				clock.fillByHMS(clock.hour, minutes, 0);
 				clock.setTime();
 			}
 		}
-
-		updateTimeStr(myhour, myminute);
 	}
 
-	if ((currentMillis - previousLightTimer >= refresh_interval) or
+	if (currentMillis - previousMillis >= interval) {
-	    (previousLightTimer > currentMillis)) { // millis() reset every ~49 days
+		previousMillis = currentMillis;
-		previousLightTimer = currentMillis;
-		ambLight = analogRead(photoPin);
 
-/* Ambient light compensation
+		if (dot)
- * ambLight can be in range of 0..1023, if it 910+, it has point to use
+			dot = false;
- * fullbright.
+		else
- * Use table comparsion (not function of ambLight) because of non-linear
+			dot = true;
- * charachteristics of led indicator, that cannot be described via simple
+	}
- * formula.
+
+	/*
+	 * 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 (ambLight >= 910) {
+
-			Display.setBrightness(100);
+	if ((clock.hour == 21) and (clock.minute == 21) and
-		} else if ((ambLight < 900) and (ambLight >= 860)) {
+	    (clock.second == 21) and (compflag)) {
-			Display.setBrightness(75);
+		clock.fillByHMS(clock.hour, clock.minute, 14);
-		} else if ((ambLight < 850) and (ambLight >= 810)) { 
+		clock.setTime();
-			Display.setBrightness(45);
+		compflag = false;
-		} else if ((ambLight < 800) and (ambLight >= 760)) {
+	}
-			Display.setBrightness(25);
+
-		} else if ((ambLight < 750) and (ambLight >= 710)) {
+	if ((clock.hour == 21) and (clock.minute == 21) and
-			Display.setBrightness(18);
+	    (clock.second == 23) and (!compflag)) {
-		} else if ((ambLight < 700) and (ambLight >= 660)) {
+		compflag = true;
-			Display.setBrightness(12);
+	}
-		} else if ((ambLight < 650) and (ambLight >= 610)) {
+
-			Display.setBrightness(10);
+	// make blinking dot
-		} else if ((ambLight < 600) and (ambLight >= 560)) {
+	if (clock.hour > 0) {
-			Display.setBrightness(7);
+		if (dot) {
-		} else if ((ambLight < 550) and (ambLight >= 410)) {
+			Display.setNumber((clock.hour * 100 + clock.minute), 2);
-			Display.setBrightness(4);
+		} else {
-		} else if ((ambLight < 400) and (ambLight >= 360)) {
+			Display.setNumber((clock.hour * 100 + clock.minute));
-			Display.setBrightness(0);
+		}
-		} else if ((ambLight < 350) and (ambLight >= 310)) {
+	} else {
-			Display.setBrightness(-3);
+		/* 0 o'clock is an exception, we don't want to see "00.00", we
-		} else if ((ambLight < 300) and (ambLight >= 260)) {
+		   want see "0.00" or "0 00", so we have to use this "hack" */
-			Display.setBrightness(-6);
+		if (dot) {
-		} else if ((ambLight < 250) and (ambLight >= 210)) {
+			d = float(clock.minute) / 100;
-			Display.setBrightness(-10);
+			Display.setNumber(d, 2);
-		} else if ((ambLight < 200) and (ambLight >= 160)) {
+		} else {
-			Display.setBrightness(-14);
+			sprintf(str, "%2d%02d", clock.hour, clock.minute);
-		} else if ((ambLight < 150) and (ambLight >= 110)) {
+			Display.setChars(str);
-			Display.setBrightness(-18);
-		} else if (ambLight < 100) {
-			Display.setBrightness(-22);
 		}
 	}
 
 	Display.refreshDisplay();
 }
 
-void updateTimeStr(uint8_t h, uint8_t m)
-{
-	if (dot) {
-		char str[5];
-		sprintf(str, "%2d.%02d", h, m);
-		Display.setChars(str);
-	} else {
-		char str[4];
-		sprintf(str, "%2d%02d", h, m);
-		Display.setChars(str);
-	}
-}
 /* vim: set filetype=cpp: */