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Files
simpleclock/simpleclock.ino

338 lines
9.2 KiB
C++

/* 7 Segment 4 Digits clock with digit point separator.
*
* It uses display module with common anode and DS1307/DS3231 RTC module to
* enhance time keeping ability of Atmega 328p based Arduino Nano
* microcontroller and 2 buttons for adjusting time. */
/* uRTCLib
* https://github.com/Naguissa/uRTCLib
* it has support for both DS1307 and DS3231, that I have.
* It is more fat than ds1307-dedicated or ds3231-dedicated lib, but I do not
* want to re-invent wheel if I have one. */
#include <uRTCLib.h>
/* SevSeg
* https://github.com/DeanIsMe/SevSeg
* it has simple api and ideally works in my case. */
#include <SevSeg.h>
/* Disable time compensation.
* At last we borrow more accurate chrystal and solder it to rtc breakboard.
*/
//#define TIMECOMP
// 0.5 second/day compensation flag.
//#define OFIVECOMP
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
uRTCLib 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
volatile bool btn_pushed = false; // is button pushed?
unsigned long previousPushTimer = 0;
// Dot blinking stuff.
volatile bool dot = true;
#ifdef TIMECOMP
// Time inaccuracy compensation flag.
volatile bool compflag1 = true;
volatile bool compflag2 = false;
const uint8_t timeSkew = 9; // Assume that clock runs faster than should.
#ifdef OFIVECOMP
volatile bool timeSkewEven = false; // Comp. 1 additional second per 2 days.
#endif
#endif
// Ambient light compensation aka night mode.
const int photoPin = A2;
volatile bool measureAmbLight = true;
unsigned int ambLight = 0; // Actual value.
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()
{
// 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
/* updateWithDelays defaults to false and it is recommended value,
* 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. */
bool leadingZeros = false;
Display.begin(hardwareConfig, numDigits, digitPins, segmentPins,
resistorsOnSegments, updateWithDelays, leadingZeros);
Display.setBrightness(100);
// Init i2c bus and setup clock address.
Wire.begin();
clock.set_rtc_address(0x68);
// If rtc returns incorrect time, reset it to some default values.
clock.refresh();
if (clock.lostPower()) {
clock.set(30, 52, 15, 6, 23, 2, 19); // Saturday, 23 Feb 2019 15:52:30
clock.lostPowerClear();
}
if ((clock.hour() > 23) || (clock.minute() > 59)) {
clock.set(30, 52, 15, 6, 23, 2, 19); // Saturday, 23 Feb 2019 15:52:30
}
/* In case of ds1307 this will be noop, but ds3231/ds3232 sometimes does
* not enable battery by default. */
clock.enableBattery();
// 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;
#ifdef TIMECOMP
// Time compensation magic.
if ((myhour == 21) and (myminute == 21) and (mysecond == 21)
and (compflag2)) {
compflag1 = true;
#ifdef OFIVECOMP
(timeSkewEven) ? timeSkewEven = false : timeSkewEven;
#endif
}
if ((myhour == 21) and (myminute == 21) and (mysecond == 23)) {
compflag1 = false;
compflag2 = true;
}
#endif
}
void loop()
{
unsigned long currentMillis = millis();
#ifdef TIMECOMP
/* Let's implement time compensation for individual rtc module time
* characteristics. In in my case quartz resonator as inaccurate as
* about +9.5 seconds per 24 hours. */
if (compflag1 && compflag2) {
#ifdef OFIVECOMP
if (timeSkewEven) {
clock.set(
(mysecond - timeSkew - 1),
clock.minute(),
clock.hour(),
clock.dayOfWeek(),
clock.day(),
clock.month(),
clock.year()
);
} else {
#endif
clock.set(
(mysecond - timeSkew),
clock.minute(),
clock.hour(),
clock.dayOfWeek(),
clock.day(),
clock.month(),
clock.year()
);
#ifdef OFIVECOMP
}
#endif
compflag2 = false;
}
#endif
if (rtcsync) {
clock.refresh();
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) {
previousPushTimer = currentMillis;
btn_pushed = true;
}
}
if (btn_pushed and
(digitalRead(hrs_btn) != LOW) and (digitalRead(min_btn) != LOW)) {
// compensate possible contact bounce with delay
if (currentMillis - previousPushTimer >= bounce_delay) {
btn_pushed = false;
}
}
if (btn_pushed) {
if (currentMillis - previousPushTimer >= adjust_interval) {
previousPushTimer = currentMillis;
if (digitalRead(hrs_btn) == LOW) {
myhour++;
(myhour > 23) ? myhour = 0 : myhour;
clock.set(
0,
myminute,
myhour,
clock.dayOfWeek(),
clock.day(),
clock.month(),
clock.year()
);
}
if (digitalRead(min_btn) == LOW) {
myminute++;
(myminute > 59) ? myminute = 0 : myminute;
clock.set(
0,
myminute,
myhour,
clock.dayOfWeek(),
clock.day(),
clock.month(),
clock.year()
);
}
}
updateTimeStr(myhour, myminute);
}
if ((currentMillis - previousLightTimer >= refresh_interval) or
(previousLightTimer > currentMillis)) { // millis() reset every ~49 days
previousLightTimer = currentMillis;
ambLight = analogRead(photoPin);
/* Ambient light compensation.
* ambLight can be in range of 0..1023, if it 910+, it has point to use
* fullbright.
* Use table comparsion (not function of ambLight) because of non-linear
* characteristics of led indicator, that cannot be described via simple
* formula. */
if (ambLight >= 910) {
Display.setBrightness(100);
} else if ((ambLight < 900) and (ambLight >= 860)) {
Display.setBrightness(75);
} else if ((ambLight < 850) and (ambLight >= 810)) {
Display.setBrightness(45);
} else if ((ambLight < 800) and (ambLight >= 760)) {
Display.setBrightness(25);
} else if ((ambLight < 750) and (ambLight >= 710)) {
Display.setBrightness(18);
} else if ((ambLight < 700) and (ambLight >= 660)) {
Display.setBrightness(12);
} else if ((ambLight < 650) and (ambLight >= 610)) {
Display.setBrightness(10);
} else if ((ambLight < 600) and (ambLight >= 560)) {
Display.setBrightness(7);
} else if ((ambLight < 550) and (ambLight >= 410)) {
Display.setBrightness(4);
} else if ((ambLight < 400) and (ambLight >= 360)) {
Display.setBrightness(0);
} else if ((ambLight < 350) and (ambLight >= 310)) {
Display.setBrightness(-3);
} else if ((ambLight < 300) and (ambLight >= 260)) {
Display.setBrightness(-6);
} else if ((ambLight < 250) and (ambLight >= 210)) {
Display.setBrightness(-10);
} else if ((ambLight < 200) and (ambLight >= 160)) {
Display.setBrightness(-14);
} else if ((ambLight < 150) and (ambLight >= 110)) {
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: */