A simple alarm clock application for Arduino

alarmclock.ino

#include <Time.h>
#include <TimeLib.h>
#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

//User editable configurations
const short dismissPin = 7;
const short snoozePin = 8;
const short buzzerPin = 13;

//Don't touch these!

//Current time
short hours = 0;
short minutes = 0;
short seconds = 0;
bool AMPM = true;

//Alarm
short ahours = 0;
short aminutes = 0;
bool aAMPM = true;
bool dismissed = false;
bool alarm = false;

String formatTime(int dhours, int dminutes, int dseconds, bool AMPM) {
  //Algorithm to generate time to display from minute and hours values
  String hours = String(dhours);
  String minutes = String(dminutes);
  String seconds = String(dseconds);
  if (dhours > 12 && !AMPM) {
    hours = String(dhours - 12);
  }
  if (hours.length() < 2) {
    hours = "0" + String(hours[0]);
  }
  if (minutes.length() < 2) {
    minutes = "0" + String(minutes[0]);
  }
  if (seconds.length() < 2) {
    seconds = "0" + String(seconds[0]);
  }
  return hours + ":" + minutes + " " + seconds + " " + (AMPM ? "AM" : "PM");
}

void updateSetupScreen(String message, int hours, int minutes, int seconds, bool AMPM) {
  lcd.setCursor(0,0);
  lcdWrite(lcd, message + formatTime(hours, minutes, seconds, AMPM));
}

void lcdWrite(LiquidCrystal lcd, String message) {
  lcd.clear();
  lcd.print(message);
}

void setup() {
  Serial.begin(9600);
  pinMode(dismissPin, INPUT);
  pinMode(snoozePin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  
  //Set time
  bool setupComplete = false;
  int mode = 1; //Which digit is being modified
  String message = "Set: ";
  while (!setupComplete) {
    int set = digitalRead(dismissPin);
    int increment = digitalRead(snoozePin);

    if (set == HIGH) {
      if (mode == 3) { //Message 
        lcdWrite(lcd, "Set Alarm");
        delay(1000);
      }
      mode++;
      delay(250);
    } else if (increment == HIGH) {
      switch (mode) {
        case 1:
          if (hours == 12) {
            hours = 1;
            AMPM = !AMPM;
          } else {
            hours++;
          }
          break;
        case 2:
          minutes += minutes <= 59 && minutes >= 50 ? -50 : 10;
          break;
        case 3:
          minutes += String(minutes)[1] == '9' || (minutes < 10 && minutes == 9) ? -9 : 1;
          break;
        case 4:
          if (ahours == 12) {
            ahours = 1;
            aAMPM = !aAMPM;
          } else {
            ahours++;
          }
          break;
        case 5:
          aminutes += aminutes <= 59 && aminutes >= 50 ? -50 : 10;
          break;
        case 6:
          aminutes += String(aminutes)[1] == '9' || (aminutes < 10 && aminutes == 9) ? -9 : 1;
      }
      delay(50);
    }
    if (mode >= 7) {
      setupComplete = true;
      //Serial.print("ahours: " + String(ahours) + "\naminutes: " + String(aminutes) + "\naAMPM" + String(aAMPM))
    } else if (mode <= 6 && mode >= 4) {
      updateSetupScreen("", ahours, aminutes, 0, aAMPM);
    } else {
      updateSetupScreen("Set: ", hours, minutes, seconds, AMPM);
    }
    delay(50);
  }

  //Set internal time to inputted
  setTime(AMPM ? hours : hours + 12, minutes, 0, 0, 0, 0);

  lcdWrite(lcd,"Time set!");
  delay(1000);
}

void loop() {
  int d = 1000; //Delay if alarm is on
  int time[] = {hour(),minute(),second(), isAM()};
  lcd.setCursor(0,0);
  lcd.print(formatTime(time[0], time[1], time[2], time[3]));
  if (digitalRead(dismissPin) == HIGH && alarm) {
    dismissed = true;
  } else if (digitalRead(snoozePin) == HIGH && alarm) {
    if (aminutes > 55) {
      ahours++;
      aminutes = 55 - aminutes;
    } else {
      aminutes += 5;
    }
  }
  if (time[0] == (aAMPM ? ahours : ahours + 12) && time[1] == aminutes && time[3] == aAMPM && !dismissed) {
    //Alarm
    tone(buzzerPin, 3000, 50);
    alarm = true;
    d = 100; //Shorter delay when alarm is going to catch snooze and dismiss presses 
  }
  delay(d);
}