Add ability to correct 0.5 second per day

+ Added ability to fix timw skew of 1 second per two
   days
* Removed text of license as it shipped as file
* Fixed some grammar mistekes
* compflag now boolean
* Coding style fixes
* Tinker a bit values for brightness, again. Make display
   more dusk.

--HG--
branch : phtoresistor

.hgtags

@@ -1,3 +1,4 @@
 ee4999ebdd2d1b54512facafdd03c8a530ea4bfa v1.0
 1167bd4b622768ed17e116a4cbac3db90031e6f8 v1.1
 109112211e454e608911949914eaa2722fbfed7d v1.2
+20da600eb0ccd51e73722f3bdfa5833df4dab826 v1.3

README.md

@@ -12,6 +12,8 @@
 * 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
 
@@ -24,12 +26,3 @@
 ### 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

@@ -34,6 +34,11 @@ bool dot = true;
 
 /* time inaccuracy compensation flag */
 bool compflag = true;
+const uint8_t timeSkew = 6; // assume that clock runs faster than should
+bool timeSkewEven = false;  // comp. 1 additional second per 2 days
+
+/* ambient light compensation aka night mode */
+const int photoPin = A2;
 
 void setup()
 {
@@ -43,7 +48,12 @@ 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
-	bool updateWithDelays = false;   // Default. Recommended
+	/* updateWithDelays defaults to false and it is recommended value,
+	 * but i was unable to make my display to change brightness 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 */
@@ -69,6 +79,9 @@ void setup()
 	// setup control buttons
 	pinMode(hrs_btn, INPUT_PULLUP);
 	pinMode(min_btn, INPUT_PULLUP);
+
+	// setup ambient brigtness sensor
+	pinMode(photoPin, INPUT);
 }
 
 void loop()
@@ -77,6 +90,7 @@ void loop()
 	currentPushTimer = currentMillis;
 	char str[4];
 	float d;
+	unsigned int ambLight = analogRead(photoPin);
 
 	clock.getTime();
 
@@ -129,13 +143,23 @@ void loop()
 	/*
 	 * 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
+	 * +/- about 6.5 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);
+
+		if (timeSkewEven) {
+			timeSkewEven = false;
+			clock.fillByHMS(clock.hour, clock.minute,
+			                (clock.second - timeSkew - 1));
+		} else {
+			timeSkewEven = true;
+			clock.fillByHMS(clock.hour, clock.minute,
+			                (clock.second - timeSkew));
+		}
+
 		clock.setTime();
 		compflag = false;
 	}
@@ -164,6 +188,32 @@ void loop()
 		}
 	}
 
+	/* ambient light compensation
+	 * ambLight can be in range of 0..1023, if it 800, it has point to use
+	 * fullbright
+	 */
+	if (ambLight >= 940) {
+		Display.setBrightness(100);
+	} else if ((ambLight < 900) and (ambLight >= 840)) {
+		Display.setBrightness(75);
+	} else if ((ambLight < 800) and (ambLight >= 735)) {
+		Display.setBrightness(40);
+	} else if ((ambLight < 700) and (ambLight >= 635)) {
+		Display.setBrightness(15);
+	} else if ((ambLight < 600) and (ambLight >= 530)) {
+		Display.setBrightness(12);
+	} else if ((ambLight < 500) and (ambLight >= 430)) {
+		Display.setBrightness(10);
+	} else if ((ambLight < 400) and (ambLight >= 325)) {
+		Display.setBrightness(8);
+	} else if ((ambLight < 300) and (ambLight >= 220)) {
+		Display.setBrightness(6);
+	} else if ((ambLight < 200) and (ambLight >= 110)) {
+		Display.setBrightness(4);
+	} else if (ambLight < 100) {
+		Display.setBrightness(3);
+	}
+
 	Display.refreshDisplay();
 }