Team The Underdog:

Published June 2, 2017 © GPL3+

Arduino Alarm Clock

An alarm clock that uses an Arduino UNO, a buzzer, DS1307 rtc, and usb port.

IntermediateWork in progress34,292

Things used in this project

Hardware components

Arduino UNO

Buzzer

Buzzer goes on pin 11 and ground

Male/Female Jumper Wires

These will be necessary when you solder the rtc

Male Header 40 Position 1 Row (0.1")

Real Time Clock (RTC)

rtc DS1307 https://www.amazon.com/JBtek%C2%AE-DS1307-AT24C32-memory-Arduino/dp/B00UUR8GJU

Jumper wires (generic)

Adafruit RGB Backlight LCD - 16x2

Rotary potentiometer (generic)

Resistor 100 ohm

USB-A to Micro-USB Cable

Breadboard (generic)

Hand tools and fabrication machines

Soldering iron (generic)

Story

My project is an Arduino alarm clock. I was curious to see if I can make a functional alarm clock with just an Arduino board and an RTC. At first, the numbers only appeared on the serial monitor because I struggled with getting the LCD to light up. I wanted to go step by step in the process so that I can fully understand what was going on. This can be seen here where I prioritized connecting the RTC with the Arduino board to see if I can manipulate the date and time in the code:

Serial Numbers

Then, with the help of the circuit model made by Ali Hamza, I was able to get my LCD to light up. I soldered the RTC in the pins GND, SDA, SCL, and VCC. Unfortunately, because she used a different rtc (real time clock), I could not efficiently use her code and library.

Bright LCD but no numbers or letters...the yellow is the usb cable

A lot of my time was spent trying to find a way to connect both my rtc and LCD. Although I take a computer science class at school, I never really worked with code that's this expansive. Finally, I did find some code that I could use to get both my rtc and LCD together and accurately show the time. It didn't work very well initially and showed a lot of errors in the date/time. I had to change the variables on top (all the #'s) and upload the correct library for it to work. The buzzer came later where I simply added the standard code for a buzzer on the arduino board and changed it so that it would beep at certain time intervals, like a real clock!

And more pictures!

I used a 120 ohm resistor but generally any resistor with a lower resistance can work out

Potentiometer

Close up view of the wires

Buzzer!

Here's a closeup of the LCD screen

If you follow the steps on Ali Hamza's site on where the wires go, you can then upload the rtc DS1307 in place of the rtc she uses and use the code I modified to suit for the DS1307 and the buzzer. Change the date and time to fit the laptop's date/time and it should be all set!

Code

Arduino Alarm Clock With DS1307 rtc

#include <Wire.h>
#include "RTClib.h"
#include <LiquidCrystal.h>
LiquidCrystal lcd(2,3,4,5,6,7);
//LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
RTC_DS1307 RTC;
#define buz 11
const int buzzer = 11;
 
void setup () {
    Serial.begin(9600);
    Wire.begin();
    RTC.begin();
    lcd.begin(16, 2);
    pinMode(buzzer, OUTPUT);
 
  if (! RTC.isrunning()) {
   Serial.println("RTC is NOT running!");
    // following line sets the RTC to the date & time this sketch was compiled
  //RTC.adjust(DateTime(__DATE__, __TIME__)); // Use ONCE then comment out and reload
  RTC.adjust(DateTime(2017,05,18,11,10,0)); // Set time manually ONCE as above
  }
}

void loop () {
    DateTime now = RTC.now();
    lcd.setCursor(0, 0);
    lcd.print(now.day(), DEC);
    lcd.print('/');
    lcd.print(now.month(), DEC);
    lcd.print('/');
    lcd.print(now.year(), DEC);
    lcd.print(' ');
    lcd.setCursor(0, 2);
     if (now.hour()<10)
    lcd.print('0');
    lcd.print(now.hour(), DEC);
    lcd.print(':');
     if (now.minute()<10)
    lcd.print('0');
    lcd.print(now.minute(), DEC);
    lcd.print(':');
    if (now.second()<10)
    lcd.print('0');
    lcd.print(now.second(), DEC);
    lcd.setCursor(12, 0);
    if (now.hour() == 10 && now.minute() == 53){
      Buzz();
    }
    
}
void Buzz() {
    tone(buzzer, 1000); // Send 1KHz sound signal...
    delay(500);        // ...for 1 sec
    noTone(buzzer);     // Stop sound...
    delay(500);        // ...for 1sec
  }

 void printTime() {
  int dayofweek;
   switch(dayofweek){
     case 1: 
     lcd.print("Mon");
     break;
     case 2:
     lcd.print("Tue");
     break;
     case 3:
     lcd.print("Wed");
     break;
     case 4:
     lcd.print("Thu");
     break;
     case 5:
     lcd.print("Fri");
     break;
     case 6:
     lcd.print("Sat");
     break;
     case 0:
     lcd.print("Sun");
     break;
    delay(1000);

   }
}

Credits

clicshnycorg

0 projects • 2 followers

Thanks to Ali Hamza, Jeelab's RTC Library, and MarkiT.

Arduino Alarm Clock

Things used in this project

Hardware components

Hand tools and fabrication machines

Story

Schematics