Arduino HPDL1414 Retro Clock with Set and Alarm Functions

#include <HPDL1414.h>
#include <RTClib.h>
#include <Wire.h>

const byte dataPins[7] = {2, 3, 4, 5, 6, 7, 8};  // Segment data pins: D0 - D6
const byte addrPins[2] = {A1, A2};               // Segment address pins: A0, A1
const byte wrenPins[] = {A0, A3};                // Write Enable pins (left to right)

RTC_DS3231 rtc;
char msg[] = "         *** MICRO CLOCK - MIRCEMK ***        ";
char t[32];
HPDL1414 hpdl(dataPins, addrPins, wrenPins, sizeof(wrenPins));

// Button pins
const int buttonHourPin = 9;
const int buttonMinutePin = 10;
const int buttonSetPin = 11;

// Buzzer pin
const int buzzerPin = 12;  // Add a pin for the buzzer

// Variables for setting time and alarm manually
int hours = 0;
int minutes = 0;
int alarmHours = 0;
int alarmMinutes = 0;
bool setMode = false;      // Time setting mode flag
bool alarmMode = false;    // Alarm setting mode flag
bool alarmEnabled = false; // Alarm enabled flag
bool alarmActive = false;  // Alarm active (sounding) flag
bool alarmAcknowledged = false; // Alarm acknowledged (stopped) flag

// Buzzer timing
unsigned long previousMillis = 0;
const long beepInterval = 500;  // 500ms on, 500ms off
bool buzzerState = false;       // To track buzzer state (on/off)

void setup() {
  Serial.begin(9600);
  Wire.begin();
  hpdl.begin();
  hpdl.clear();

  // Set up buttons and buzzer
  pinMode(buttonHourPin, INPUT_PULLUP);
  pinMode(buttonMinutePin, INPUT_PULLUP);
  pinMode(buttonSetPin, INPUT_PULLUP);
  pinMode(buzzerPin, OUTPUT);
  digitalWrite(buzzerPin, LOW);  // Make sure the buzzer is off initially

  // Display scrolling message at startup
  for (byte i = 0; i < (sizeof(msg) / sizeof(char)); i++) {
    for (byte j = 0; j < 16; j++) {
      hpdl.setCursor(j);
      if (i + j < (sizeof(msg) / sizeof(char))) {
        hpdl.print(msg[i + j]);
      } else {
        hpdl.print(" ");
      }
    }
    delay(200);
  }

  rtc.begin();
  // Initialize time variables from the RTC
  DateTime now = rtc.now();
  hours = now.hour();
  minutes = now.minute();
}

void loop() {
  // Get the current time from the RTC
  DateTime now = rtc.now();

  // Check if the alarm is active (buzzer sounding)
  if (alarmActive) {
    unsigned long currentMillis = millis();
    
    // Toggle the buzzer every 500ms (buzzerState controls on/off)
    if (currentMillis - previousMillis >= beepInterval) {
      previousMillis = currentMillis;  // Save the last time the buzzer toggled
      buzzerState = !buzzerState;      // Toggle the buzzer state
      digitalWrite(buzzerPin, buzzerState ? HIGH : LOW);  // Turn the buzzer on or off
    }

    // Check if D11 is pressed to stop the alarm
    if (digitalRead(buttonSetPin) == LOW) {
      alarmActive = false;  // Stop the alarm
      alarmAcknowledged = true;  // Mark the alarm as acknowledged
      digitalWrite(buzzerPin, LOW);  // Turn off the buzzer
      delay(500);  // Debounce delay
      return;  // Return to normal loop operation
    }
  }

  // Check if we are in time or alarm setting mode
  if (setMode) {
    // Display the manually set time
    sprintf(t, "%02d-%02d", hours, minutes);
    hpdl.clear();
    hpdl.print(t);

    // Check if buttons to adjust hours or minutes are pressed
    if (digitalRead(buttonHourPin) == LOW) {
      hours = (hours + 1) % 24;  // Increment hours and roll over after 23
      delay(200);  // Debouncing
    }
    if (digitalRead(buttonMinutePin) == LOW) {
      minutes = (minutes + 1) % 60;  // Increment minutes and roll over after 59
      delay(200);  // Debouncing
    }
  } else if (alarmMode) {
    // Display the manually set alarm time
    sprintf(t, "A%02d-%02d", alarmHours, alarmMinutes);
    hpdl.clear();
    hpdl.print(t);

    // Check if buttons to adjust alarm hours or minutes are pressed
    if (digitalRead(buttonHourPin) == LOW) {
      alarmHours = (alarmHours + 1) % 24;  // Increment alarm hours and roll over after 23
      delay(200);  // Debouncing
    }
    if (digitalRead(buttonMinutePin) == LOW) {
      alarmMinutes = (alarmMinutes + 1) % 60;  // Increment alarm minutes and roll over after 59
      delay(200);  // Debouncing
    }
  } else {
    // Normal operation: Display the current time from the RTC
    sprintf(t, "%02d-%02d-%02d", now.hour(), now.minute(), now.second());
    hpdl.clear();
    hpdl.print(t);

    // Check if the current time matches the alarm time and alarm is not acknowledged
    if (alarmEnabled && !alarmAcknowledged && now.hour() == alarmHours && now.minute() == alarmMinutes && now.second() == 0) {
      alarmActive = true;  // Mark the alarm as active
      previousMillis = millis();  // Initialize the timer for buzzer beeping
    }

    // Reset the alarm acknowledgement flag if the minute has changed
    if (now.minute() != alarmMinutes) {
      alarmAcknowledged = false;  // Allow the alarm to trigger again when the time matches next
    }
  }

  // Check if the Set button (buttonSetPin) is pressed to toggle between modes
  if (digitalRead(buttonSetPin) == LOW && !alarmActive) {
    if (setMode) {
      // Exiting time set mode, update the RTC with the manually set time
      rtc.adjust(DateTime(2024, 1, 1, hours, minutes, 0));  // Arbitrary date
      setMode = false;
      alarmMode = true;  // Move to alarm setting mode
    } else if (alarmMode) {
      // Exiting alarm set mode, enable the alarm
      alarmEnabled = true;
      alarmMode = false; // Back to normal mode
    } else {
      // Enter time setting mode
      setMode = true;
    }
    delay(500);  // Debouncing delay
  }
}