Simple Alarm Clock | RTC DS1302 + LCD + pi Pico

//pi pico version//
//PROGRAM BY: RANDY N. CAÑADA
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#include <LiquidCrystal_I2C.h>
#include <ThreeWire.h>
#include <RtcDS1302.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);//sda=4,sda=5 //use your own LCD address. Use I2c scanner
ThreeWire myWire(10, 11, 12); // DAT=GP10, CLK=GP11, RST=GP12
RtcDS1302<ThreeWire> Rtc(myWire);

const int pinCLK = 14;
const int pinDT  = 15;
const int pinSW  = 16;
const int pinBuzzer = 17;

enum TimeField {
  NONE, YEAR, MONTH, DAY, HOUR, MINUTE, SECOND,
  ALARM_HOUR, ALARM_MINUTE, DONE
};
enum SetupMode { MODE_NONE, MODE_TIME, MODE_ALARM, MODE_MENU };
SetupMode setupMode = MODE_NONE;
TimeField currentField = NONE;

int year, month, day, hour, minute, second;
int alarmHour = 6;
int alarmMinute = 0;
bool settingMode = false;
bool alarmActive = false;
bool buzzerOn = false;
bool alarmDismissed = false;

unsigned long buzzerStartTime = 0;
const unsigned long buzzerDuration = 10000;

int lastEncoded = 0;
unsigned long lastRotateTime = 0;
const unsigned long rotateDebounce = 170;

bool swHeld = false;
bool longPressTriggered = false;
unsigned long swPressStart = 0;
const unsigned long longPressDuration = 1000;

int lastSecond = -1;
TimeField lastField = NONE;
int lastValue = -1;

int menuIndex = 0; // 0 = Set Time, 1 = Set Alarm

void setup() {
  Wire.setSDA(4);
  Wire.setSCL(5);
  lcd.init();
  lcd.backlight();
  Rtc.Begin();

  // Load RTC values into vars
  RtcDateTime now = Rtc.GetDateTime();
  year   = now.Year();
  month  = now.Month();
  day    = now.Day();
  hour   = now.Hour();
  minute = now.Minute();
  second = now.Second();

  pinMode(pinCLK, INPUT_PULLUP);
  pinMode(pinDT, INPUT_PULLUP);
  pinMode(pinSW, INPUT_PULLUP);
  pinMode(pinBuzzer, OUTPUT);
  digitalWrite(pinBuzzer, LOW);

  Serial.begin(9600);
}

void loop() {
  RtcDateTime now = Rtc.GetDateTime();

  // Reset alarmDismissed when minute changes
  static int lastAlarmMinute = -1;
  if (now.Minute() != lastAlarmMinute) {
    alarmDismissed = false;
    lastAlarmMinute = now.Minute();
  }

  // Trigger alarm
  if (alarmActive && !alarmDismissed && now.Hour() == alarmHour && now.Minute() == alarmMinute && !buzzerOn) {
    buzzerOn = true;
    buzzerStartTime = millis();
    digitalWrite(pinBuzzer,HIGH);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alarm Ringing!");
  }

  // Auto-silence
  if (buzzerOn && millis() - buzzerStartTime > buzzerDuration) {
    buzzerOn = false;
    alarmDismissed = true;
    digitalWrite(pinBuzzer, LOW);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alarm Stopped");
  }

  // Manual silence
  if (buzzerOn && digitalRead(pinSW) == LOW) {
    buzzerOn = false;
    alarmDismissed = true;
    digitalWrite(pinBuzzer, LOW);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alarm Stopped");
    delay(1000);
  }

  // ---------------- Idle mode ----------------
  if (!settingMode) {
    if (now.Second() != lastSecond) {
      lastSecond = now.Second();
      char dateBuffer[11];
      sprintf(dateBuffer, "%02d/%02d/%04d", now.Day(), now.Month(), now.Year());
      char timeBuffer[9];
      sprintf(timeBuffer, "%02d:%02d:%02d", now.Hour(), now.Minute(), now.Second());
      lcd.setCursor(0, 0);
      lcd.print("Date: "); lcd.print(dateBuffer); lcd.print("   ");
      lcd.setCursor(0, 1);
      lcd.print("Time: "); lcd.print(timeBuffer); lcd.print("   ");
    }

    // Long press → enter menu
    if (digitalRead(pinSW) == LOW) {
      if (!swHeld) {
        swPressStart = millis();
        swHeld = true;
        longPressTriggered = false;
      } else if (!longPressTriggered && millis() - swPressStart > longPressDuration) {
        settingMode = true;
        longPressTriggered = true;
        setupMode = MODE_MENU;
        menuIndex = 0;
        showMenu();
        delay(500);
      }
    } else {
      swHeld = false;
    }
    return;
  }

  // ---------------- Menu ----------------
  if (setupMode == MODE_MENU) {
    handleMenu();
  } else {
    handleEditing();
  }
}

// ---------------- Menu Functions ----------------
void showMenu() {
  lcd.setCursor(0, 0);
  lcd.print(menuIndex == 0 ? "> Set Time      " : "  Set Time     "); // add spaces to clear leftover
  lcd.setCursor(0, 1);
  lcd.print(menuIndex == 1 ? "> Set Alarm    " : "  Set Alarm    "); // add spaces
}


void handleMenu() {
  // Rotary encoder
  int MSB = digitalRead(pinCLK);
  int LSB = digitalRead(pinDT);
  int encoded = (MSB << 1) | LSB;
  int sum = (lastEncoded << 2) | encoded;

  if (millis() - lastRotateTime > rotateDebounce) {
    if (sum == 0b1101 || sum == 0b0100 || sum == 0b0010 || sum == 0b1011) {
      menuIndex = (menuIndex + 1) % 2;
      lastRotateTime = millis();
    } else if (sum == 0b1110 || sum == 0b0111 || sum == 0b0001 || sum == 0b1000) {
      menuIndex = (menuIndex == 0) ? 1 : 0;
      lastRotateTime = millis();
    }
    showMenu();

  }
  lastEncoded = encoded;

  // Short press → select
  if (digitalRead(pinSW) == LOW && !swHeld && !longPressTriggered) {
    swHeld = true;
    if (menuIndex == 0) { // Set Time
      setupMode = MODE_TIME;
      currentField = YEAR;
      lcd.clear();
      lcd.setCursor(0, 0); lcd.print("Set Time");
    } else { // Set Alarm
      setupMode = MODE_ALARM;
      currentField = ALARM_HOUR;
      lcd.clear();
      lcd.setCursor(0, 0); lcd.print("Set Alarm");
    }
    delay(500);
    lastField = NONE; // force LCD update
    lastValue = -1;
  } else if (digitalRead(pinSW) == HIGH) {
    swHeld = false;
    longPressTriggered = false;
  }
}

// ---------------- Editing Functions ----------------
void handleEditing() {
  int MSB = digitalRead(pinCLK);
  int LSB = digitalRead(pinDT);
  int encoded = (MSB << 1) | LSB;
  int sum = (lastEncoded << 2) | encoded;

  if (millis() - lastRotateTime > rotateDebounce) {
    if (sum == 0b1101 || sum == 0b0100 || sum == 0b0010 || sum == 0b1011) { incrementField(currentField); lastRotateTime = millis();}
    if (sum == 0b1110 || sum == 0b0111 || sum == 0b0001 || sum == 0b1000) { decrementField(currentField); lastRotateTime = millis();}
  }
  lastEncoded = encoded;

  // LCD update
  int currentValue = getFieldValue(currentField);
  if (currentField != lastField || currentValue != lastValue) {
    lastField = currentField;
    lastValue = currentValue;

    lcd.setCursor(0, 0);
    if (currentField == DONE) {
      lcd.print("Press to Save   ");
      lcd.setCursor(0, 1);
      lcd.print("                ");
    } else {
      lcd.print("Set "); lcd.print(fieldName(currentField)); lcd.print("        ");
      lcd.setCursor(0, 1);
      lcd.print("Value: "); lcd.print(paddedValue(currentField)); lcd.print("     ");
    }
  }

  // Short press confirm
  if (digitalRead(pinSW) == LOW && !swHeld && !longPressTriggered) {
    swHeld = true;

    if (setupMode == MODE_TIME) {
      if (currentField == SECOND) currentField = DONE;
      else currentField = static_cast<TimeField>(currentField + 1);
    } else if (setupMode == MODE_ALARM) {
      if (currentField == ALARM_MINUTE) currentField = DONE;
      else currentField = static_cast<TimeField>(currentField + 1);
    }

    lastField = NONE;

    if (currentField == DONE) {
      if (setupMode == MODE_TIME) {
        RtcDateTime newTime(year, month, day, hour, minute, second);
        Rtc.SetDateTime(newTime);
        lcd.clear(); lcd.print("Time Saved!");
      } else if (setupMode == MODE_ALARM) {
        alarmActive = true;
        lcd.clear(); lcd.print("Alarm Saved!");
      }
      delay(1000);
      setupMode = MODE_NONE;
      settingMode = false;
      currentField = NONE;
      lastSecond = -1;
    }
    delay(300);
  } else if (digitalRead(pinSW) == HIGH) {
    swHeld = false; longPressTriggered = false;
  }
}

// ---------------- Utility Functions ----------------
String fieldName(TimeField field) {
  switch (field) {
    case YEAR: return "Year"; case MONTH: return "Month"; case DAY: return "Day";
    case HOUR: return "Hour"; case MINUTE: return "Minute"; case SECOND: return "Second";
    case ALARM_HOUR: return "AlarmHr"; case ALARM_MINUTE: return "AlarmMin";
    default: return "";
  }
}

String paddedValue(TimeField field) {
  char buffer[5];
  int value = getFieldValue(field);
  if (field == YEAR) sprintf(buffer, "%04d", value);
  else sprintf(buffer, "%02d", value);
  return String(buffer);
}

int getFieldValue(TimeField field) {
  switch (field) {
    case YEAR: return year; case MONTH: return month; case DAY: return day;
    case HOUR: return hour; case MINUTE: return minute; case SECOND: return second;
    case ALARM_HOUR: return alarmHour; case ALARM_MINUTE: return alarmMinute;
    default: return 0;
  }
}

void incrementField(TimeField field) {
  switch (field) {
    case YEAR: year++; break;
    case MONTH: month = (month % 12) + 1; break;
    case DAY: day = (day % 31) + 1; break;
    case HOUR: hour = (hour + 1) % 24; break;
    case MINUTE: minute = (minute + 1) % 60; break;
    case SECOND: second = (second + 1) % 60; break;
    case ALARM_HOUR: alarmHour = (alarmHour + 1) % 24; break;
    case ALARM_MINUTE: alarmMinute = (alarmMinute + 1) % 60; break;
    default: break;
  }
}

void decrementField(TimeField field) {
  switch (field) {
    case YEAR: year = max(2000, year - 1); break;
    case MONTH: month = (month == 1) ? 12 : month - 1; break;
    case DAY: day = (day == 1) ? 31 : day - 1; break;
    case HOUR: hour = (hour == 0) ? 23 : hour - 1; break;
    case MINUTE: minute = (minute == 0) ? 59 : minute - 1; break;
    case SECOND: second = (second == 0) ? 59 : second - 1; break;
    case ALARM_HOUR: alarmHour = (alarmHour == 0) ? 23 : alarmHour - 1; break;
    case ALARM_MINUTE: alarmMinute = (alarmMinute == 0) ? 59 : alarmMinute - 1; break;
    default: break;
  }
}