Introduction: How to Make a Arduino Digital Clock

About: I am an electronic hobiest and computer science engineer . Who loves and enjoys making cool projects.

Digital clocks are one of the great invention in the field of science.

Have you ever wondered "How to make your own digital clocks , just like in movies! "????

Well i have also spent ,my childhood in a dream to built my very own digital clock.. so i built one for my self ...

And am going to show you, How you can built an amazing digital clock with little ease and little components all by yourself....

I have used 4 7 segment common anode display to display the digits, 3 SPDT switches , which i took apart from an old mouse, some wires and an arduino. we can set the time holding the adjust key and pressing the minute or hour key to change the minute or the hour to our need..!

So Lets get started...!

Step 1: Components Required

Here the Components that you will Require :

1. An Arduino uno.

2. 4 7 segment common anode displays (if you have a 4 digit seven segment , don't worry the circuitry is same for both of them).

you can buy them from snapdeal , they are great ! i would recommend them from the site.

3. 3 spdt Switches (which i scavenged from an old mouse ).

4.some wires and jumper wires (any one will do!).

5. A breadboard.

6. 4 1kohm resistors.

Step 2: Wiring the Displays in the Breadboard!

Make the connections as shown in the picture above.. its quite simple.!

Take care of the connections , as coz there are too many wires you might get confuse.

Remmenber All a,b,c,d,e,f,g,dot segments of 4 displays are connected together.... and the com of every display i.e 3 and 8 are connected together with the resitors...

Do not worry!! , go slowly,and have some patience , you can do it.

Step 3: Adding the Resistors and the Keys

Attach 1kohm resistor with each com of the displays ... as shown in the figure..!

Add the Spdt switches or if you have push on buttons that would be great !...

Step 4: Connecting to Arduino

Now the connections are done for the display and the switches ... now time is to connect them to the brain..

it is simple..

For segment pins!

a to pin 2

b to pin 3

c to pin 4

d to pin 5

e to pin 6

f to pin 7

g to pin 8

dot to pin 9

For display pins

display 1 to pin 10

display 2 to pin 11

display 3 to pin 12

dispaly 4 to pin 13

now for the keys

key 1 which is the adjust switches ...

key 2 and key 3 are hour changing and minute changing switches..

we have to hold the adjust key1 and press the desire key to change the hour or the minute..!

see the pic above for the connection for the keys .. we have used the analog pins and used them as digital input pins... yes thats true we can use them as digital i/o pins too..

Step 5: Adding the Code!!!!

Now the most cool part ... writing and adding the code to the arduino....

I have attached the code and the time library file .. for calculating the time and displaying it....

In the code the hour() function tells us the hour, and the minute() function the minute , from the time we have switched on the board. the time fades dies when the power to the board is cut of.. and it starts again from 00:00 every time...

Also i have attached a 12 hour format code too. It just uses hourFormat12() function to get the 12 hr format.

By default the Time library returns 24hr formated time.


Please add the Time Folder in, in your Arduino's libraries folder.

eg in my system:

C:\Program Files (x86)\Arduino\libraries

Do feel flexible in changing the code for your needs ... and if you have some quarries feel free to ask.

Have fun making it...

note: I have updated the file as it was deprecated in newer versions of Arduino IDE.