Overview
Things
Story

Youtube tutorial
Notes
Notes for Downloading Code

Published June 23, 2020

Arduino Alarm

With the use of a DS1307 RTC Module, you can accurately set alarms and read the time on an LCD Display.

BeginnerFull instructions provided8,485

Things used in this project

Hardware components

Arduino Mega 2560

LCD Display

DS1307 RTC Module

Active Buzzer Module

Push Button Module

Breadboard

Jumper Wire

Software apps and online services

Arduino IDE

Story

Youtube tutorial:

Notes:

When downloading the code remember to download the code twice the first time with this line not commented out and the second time with it commented out.

 //clock.setDateTime(__DATE__, __TIME__);

Notes for Downloading Code:

When downloading the code make a new sketch and add 2 new tabs and paste each sketch of the code into these tabs.

Code

#include <Wire.h>
#include <DS3231.h>
#include <LiquidCrystal.h>

LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
DS3231 clock;
RTCDateTime dt;

int buzzer = 2; //Alarm
int button = 4; //Snooze
int button_read;
bool alarm_set;
bool alarm_beep;
String alarm_hour;
String alarm_min;
String alarm_AM_PM;
int time_hour;
String time_AM_PM;
int i; //Frequency of Alarm

void setup() {

  lcd.begin(16, 2);

  Serial.begin(9600);

  pinMode(buzzer, OUTPUT);
  pinMode(button, INPUT_PULLUP);

  clock.begin();
    //clock.setDateTime(__DATE__, __TIME__);

  lcd.setCursor(6, 1);
  lcd.print(" Set Alarm");

  Serial.print("Enter Hour of Alarm");
  Serial.println();

  alarm_set =  false;
  alarm_beep = true;
}

void loop() {
  dt = clock.getDateTime();

  if (alarm_hour == 0) {
    if (Serial.available() > 0) {
      alarm_hour = Serial.readString();
      Serial.println("Alarm Hour Set: " + alarm_hour);
      lcd.clear();
      Serial.print("Enter Minute of Alarm");
      Serial.println();
      Serial.end();
      Serial.begin(9600);
    }
  }
  if (alarm_min == 0) {
    if (Serial.available() > 0) {
      alarm_min = Serial.readString();
      Serial.println("Alarm Minute Set: " + alarm_min);
      lcd.clear();
      Serial.print("Enter Ante Meridiem of Alarm");
      Serial.println();
      Serial.end();
      Serial.begin(9600);
    }
  }
  if (alarm_AM_PM == 0) {
    if (Serial.available() > 0) {
      alarm_AM_PM = Serial.readString();
      Serial.println("Alarm Ante Meridiem Set: " + alarm_AM_PM);
      lcd.clear();
      Serial.print("Alarm Set!");
      Serial.println();
      Serial.end();
      Serial.begin(9600);
      alarm_set = true;
    }
  }

  Time_Display();

  Alarm_Display();

  if ((alarm_beep == true) && (alarm_set == true) && (alarm_min.toInt() == dt.minute) && (alarm_hour.toInt() == time_hour) && (time_AM_PM == alarm_AM_PM)) {
    for (i = 0; i < 80; i++)
    {
      digitalWrite(buzzer, HIGH);
      delay(1);
      digitalWrite(buzzer, LOW);
      delay(1);
      Time_Display();
    }
    for (i = 0; i < 100; i++)
    {
      digitalWrite(buzzer, HIGH);
      delay(2);
      digitalWrite(buzzer, LOW);
      delay(2);
      Time_Display();
    }
    button_read = digitalRead(button);
    if (button_read == LOW) {
      alarm_beep = false;
      Time_Display();
    }
  }
}

void Alarm_Display()  {
  
  Time_Display();
  
  lcd.setCursor(0, 1);
  lcd.print("Alarm:");

  if (alarm_set == true) {
    if (alarm_hour.toInt() > 9) {
      lcd.setCursor(6, 1);
      lcd.print(alarm_hour.toInt());
    }
    else {
      lcd.setCursor(7, 1);
      lcd.print(alarm_hour.toInt());
    }

    lcd.setCursor(8, 1);
    lcd.print(":");

    if (alarm_min.toInt() > 9) {
      lcd.setCursor(9, 1);
      lcd.print(alarm_min.toInt());
    }
    else {
      lcd.setCursor(9, 1);
      lcd.print("0");
      lcd.setCursor(10, 1);
      lcd.print(alarm_min.toInt());
    }

    lcd.setCursor(12, 1);
    lcd.print(alarm_AM_PM);

    lcd.setCursor(11, 1);
    lcd.print(" ");
    lcd.setCursor(14, 1);
    lcd.print("    ");
  }
  Time_Display();
}

void Time_Display()  {
  lcd.setCursor(0, 0);
  lcd.print("Time:");

  if (dt.hour > 12) {
    time_hour = (dt.hour - 12);
    if (time_hour > 9) {
      lcd.setCursor(6, 0);
      lcd.print(time_hour);
    }
    else {
      lcd.setCursor(7, 0);
      lcd.print(time_hour);
    }

    lcd.setCursor(8, 0);
    lcd.print(":");

    if (dt.minute > 9) {
      lcd.setCursor(9, 0);
      lcd.print(dt.minute);
    }
    else {
      lcd.setCursor(9, 0);
      lcd.print("0");
      lcd.setCursor(10, 0);
      lcd.print(dt.minute);
    }
    if (dt.hour != 12) {
      lcd.setCursor(12, 0);
      lcd.print("PM\n");
      time_AM_PM = "PM\n";
    }
    else {
      lcd.setCursor(12, 0);
      lcd.print("AM\n");
      time_AM_PM = "AM\n";
    }
  }
  else {
    time_hour = dt.hour;
    if (dt.hour > 9) {
      lcd.setCursor(6, 0);
      lcd.print(dt.hour);
    }
    else {
      lcd.setCursor(7, 0);
      lcd.print(dt.hour);
    }
    lcd.setCursor(8, 0);
    lcd.print(":");
    if (dt.minute > 9) {
      lcd.setCursor(9, 0);
      lcd.print(dt.minute);
    }
    else {
      lcd.setCursor(9, 0);
      lcd.print("0");
      lcd.setCursor(10, 0);
      lcd.print(dt.minute);
    }
    if (dt.hour != 12) {
      lcd.setCursor(12, 0);
      lcd.print("AM\n");
      time_AM_PM = "AM\n";
    }
    else {
      lcd.setCursor(12, 0);
      lcd.print("PM\n");
      time_AM_PM = "PM\n";
    }
  }
  lcd.setCursor(11, 0);
  lcd.print(" ");
  lcd.setCursor(14, 0);
  lcd.print(" ");
}

Arduino Alarm

Things used in this project

Hardware components

Software apps and online services

Story

Youtube tutorial:

Notes:

Notes for Downloading Code:

Schematics

Arduino Alarm Schematic

Code

Arduino Alarm

Alarm Display

Time Display

Credits

SeanMabli2

Comments

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Arduino Alarm

Arduino Alarm

Things used in this project

Hardware components

Software apps and online services

Story

Youtube tutorial:

Notes:

Notes for Downloading Code:

Schematics

Arduino Alarm Schematic

Code

Arduino Alarm

Alarm Display

Time Display

Credits

SeanMabli2

Comments

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