Introduction: My Arduino WordClock

Picture of My Arduino WordClock

Step 1: The Materials

Picture of The Materials

The list of materials for the board depends on how you plan to make the electronics, if you want an Arduino standalone or an Arduino UNO or 2009, however, this is what I used.

Step 2: 1) the Materials- LED and Resistor

Picture of 1) the Materials- LED and Resistor

To realize the proposed scheme are needed:
98 White LED
98 Resistor 470 ohm
Why 470?
I chose these resistors for this reason:
LED (ultrabrightness white) forward v is 3,3v and 25ma
,the clock will run to 9v and i want that the led will be drived at half current 12,5ma (no needs too much brightness), so:

(9-3,3)/0,0125= 456, correct misure is 470 ohm resistor.

Step 3: 2) the Materials -Standalone Arduino

Picture of 2) the Materials -Standalone Arduino

On the web and on Instructables  you will find several examples , these are the materials I used for my own PCBs, I plan to switch directly the ATMega 328 bootloader included  with that my own Arduino UNO.

-2 ceramic capacitor 22pF
-quartz 16 mhz
-2 elettrolitic capacitor 100 nF
-5v regolator voltage 78L05
-1n4007 diode

Step 4: 3) the Materials - Integrated

Picture of 3) the Materials - Integrated

3- HCF4094 shift register
4- ULN2003A Driver
ATMega 328 with bootloader

Step 5: 3) the Materials - Other Electronic Part

Picture of 3) the Materials - Other Electronic Part

-2 micro button to set hours and minutes
-a supply voltage coaxial connector
-a flat wire 26 wire with connector
-two-pole connector

Step 6: 4) the Materials - Remainder

Picture of 4) the Materials - Remainder

-IKEA Ribba frame
-carboard light, color you want to make passpartout
-cartonboard thicker to make LED holder

Step 7: LED Soldering

Picture of LED Soldering

Bend direction, anode on top right and cathode dow left
Trip the anode and a side of resistor about 2-3 mm and sold it.

Step 8: Holes Guide

Picture of Holes Guide

Positive mask to help to do the holes in a led holder
I've used a a drill with a bit of 5mm
IKEA frame with inside lucid paper with word printed through a laser print (four lucid together are need to have a solid color black).

Step 9: LED Holder Back

Picture of LED Holder Back

Led Holder back. Very important to bend in a short curve anode and cathode so don't risk to touch the rows together. Sold all the anodes and cathodes together but interrupt the cathodes between the words. In this mode you will have a parallel connection
after you have soldered all the end of anodes that you see on the right. In each cathode word you will sold a wire that will go to a pin to driver the word with the Arduino sketch. 

Step 10: LED Holder Front

Picture of LED Holder Front

Led holder front, better black color to prevent reflection
Add some buffles to prevent the light from bleeding between words.

Step 11: Layers

Picture of Layers

For a better spread of light and have a solid black I have four layers overlapped acetate, at the end I put a layer of gray and a white matt

Step 12: The PCB Board

Picture of The PCB Board

This is my personal board double layer. Has made by a professional mastering, you can easly solder all the component and have an Arduino standalone, It  works 9v or 5v supply, better 9v however.
I can send gerber file for a small fee.

Step 13: Supply Voltage Plug Connector

Picture of Supply Voltage Plug Connector

Step 14: Final Result

Picture of Final Result

Step 15:

I have used the very useful and well done Doug Jackson program that reduce brightness when you want in the day time.


TomekB12 (author)2017-10-15

HI, I have question, do I need to use your PCB board?

Or can I use standard ardunio module?

What is the difference between solution with your board and andurio module?

I do not know about it, but Im very interested to do this

Cello62 (author)TomekB122017-10-15

When I realized this board I replied the arduino with the addition of integrated to run the clock. Only with the arduino could not work. Now I do not know, maybe the arduino is changed.

TomekB12 (author)Cello622017-10-16


SamP6 (author)2015-04-06

I need the Gerber file

troydp (author)SamP62015-05-12

me too

luisrosety (author)2015-04-13

The Arduino code produces errors when compiling.

What is wrong?


failureowned (author)2014-12-26

hi... i have question ., im not good at arduino Uno ., but if i use arduino Uno instead of ATMega328 , which ports will the pins be inserted ? ., waiting for your quick response thank you .... ^_^

Cello62 (author)failureowned2014-12-26

I hope to understand well your question. If you look the photo of atmega you see A1 A2 D1 D2 etc etc. Its the same in Arduino, A is analogic pin , D is are digital pin, vcc ground the same and so on.
Look at schematic pdf.

raissapamaral (author)2014-12-02

Hello, I'm trying to do this project for one of my lectures and I'm a bit confused of how you addressed the letters with the code. I notice you've used this syntax to do it #define MINUTES Display1=Display1 | (1<<0), but how can we know which letter(block of LED's) is associated with this declaration?

Thank you very much for the tutorial, is helping me a lot!

branislav.b.tomka (author)2014-11-06

Hi, please can you give here or send me the schematic on the PCB board? It would be the best if you have eagle file for this.


Hello. The schematic is on this instructables in pdf format , or please read what i wrote time ago.

dcgchico (author)2014-02-25

You have calculated 470 Ohm resistor: (9-3,3)/0,0125=456 -> 470 Ohm

If you are using a voltage regulator so you have 5V, why don't you calculate (5-3,3)/0,0125=136->270Ohm?


Cello62 (author)dcgchico2014-02-26

Because, how you have calculated in the first formula, it works at 9v or 5v, and then its better to use 470 ohm for safety. Regards

celineabbey (author)2013-09-21

hi can i know the source code, we need this because for our thesis in the school. thanks

Cello62 (author)celineabbey2013-09-21

Hi. The source code is avaible into the instructable at the end bye.

dcgchico (author)Cello622014-02-14

I don't find the source code :-(

Cello62 (author)dcgchico2014-02-14

Look better. At the end of Step 15. Regards

543781 (author)2013-10-26

Hi, i can't find out PCB. Can you share me PCB, plz? Thanks

Smtty09 (author)2013-06-11

The picture of the elctro capacitor is 100 microfarrad but you have speced a 100 nF. Which one works? Thanks

Cello62 (author)Smtty092013-06-11

Hello, is a font problem sry, 100 microfarrad. Regards

ritzanab (author)2013-05-19

how much are the materials all together?

Cello62 (author)ritzanab2013-05-19

Hi. Never done total amount sry, but not too expansive regards

anachum (author)2013-03-19

It came out beautiful !
which program did you use for the ATMEG?
I don't see RTC? can you tell me which sketch you have in this clock?

Cello62 (author)anachum2013-03-19

Hi. The sketch file is linked in the instructables, please see all pages., it is an arduino project. Regards

F_Elite (author)2012-09-14


I think there should be more information here. How do you attach the wires from the PCB to the LEDs correctly?

Cello62 (author)F_Elite2012-09-14

You have to read better. There is a schematic diagram, and a photo of a 26 wires connector, one wire/one word, vcc, and so on. Thanks

F_Elite (author)Cello622012-09-22

Ok, fine, and do I need to put any code on the ATmega 328 or does it work unmodified?

Cello62 (author)F_Elite2012-09-22

Repeat, you have to read better. At the end there is a code that you have to load in the atmega with bootloader.

Ahmedqatar (author)2011-11-06

Great idea ..
Is there a chance to make an Arabic version?

yousuffarooq1 (author)Ahmedqatar2012-08-26

Why dont you write. Every thing in arbi like al waqt. And write the numbers in arbi i want to make a prayer time clock like this word clock but havethe clock telling me how long left

drj113 (author)Ahmedqatar2012-03-04

I know this is an old post - I would be very interested in helping with an Arabic version - You can email me at - All I need is a short instruction in how to tell the time in Arabic, and I can modify the code and cut up a stencil.

I have 24 separate words to play with, so it should be doable.


maceide (author)drj1132012-06-23

If its not to much for me to ask; would you be so kind and helpful to help me make and norwegian version?
I'll be glad to help you out with all you need:)

Cello62 (author)Ahmedqatar2011-11-06

Hi, ty for reply Do not know Arabic and I do not know quite how it is delivered on time, but I think so. The concept is to modify the program by replacing the input on the correct words, the layout is simpler. See this in the Arabic version:

Ahmedqatar (author)Cello622011-11-12

I know how this clock works and the one you sent me is cool but yet i'm not sure how to get Arabic to work with it.

Is it easy to modify the program to control the led sequence?

Cello62 (author)Ahmedqatar2011-11-13

Not so easy, but not impossible. You must study the language, in any case before you know how it is treated the time in Arabic, after taking the example in English try to see if there are similarities, if so just replacing the words, otherwise you have to add instructions.
Try to contact if you want this author
is very kind and competent, may have already done something in Arabic.

Ahmedqatar (author)Cello622011-11-14

I do have programming background .. I think it's just replacing the words..
Thanks for helping

pro2xy (author)2012-02-05

"Share a project does not mean give away components" - I thought we were talking about the designs, not the components. Sorry I misunderstood that.

"I paid several euros to have the designs and build the pcb" - The text on the instructable wasn't clearly mentioning that. "Has made by a professional mastering" gives more of an idea that you are a professional in designing PCBs. Sorry about that again.

" mine is just a request for transport cost"  - I thought that you would email a soft copy of the design or upload it here. Sorry again, misunderstanding.

"but as youI've seen i have completely shared project including wiring diagrams" - I completely agree, and honestly, following your schematics and design ideas, I'm building my own word clock! Thanks to Doug as well!

"If you have nothing to do go to to make the communist from another site please." - I dont understand this statement, please elaborate. 

Over everything, this is a very nice instructable. Hats off to you. :)

pro2xy (author)2012-02-05

Interesting to note: You say -
There is no joy in possession without sharing'

And yet -
'I can send gerber file for a small fee.'
Anyhow, I wonder how much.

Cello62 (author)pro2xy2012-02-05

Share a project does not mean give away components if your limited brain can understand that I paid several euros to have the designs and build the pcb, mine is just a request for my costs, but as you have seen i have completely shared project including wiring diagrams. If you have nothing to do go to to make the other from another site please.

sucanushie (author)2012-01-27

Do you use a DS1302? I can't seem to see it on your PCB

Cello62 (author)sucanushie2012-01-27

You don't have understood my words. I've just wrote that there is another member, Doug Jackson, that has made a word clock using Ds1302.
Look at

ddolbi1 (author)2011-11-17

Hi, if I plan on using ATMega168 and other components instead of using an arduino, what do I do about the "to arduino" connections on the schematic?
Do I just completely ignore it and imagine it isn't there?

Cello62 (author)ddolbi12011-11-18

Hi, ty for reply.
Yes you have to ignore this part (CN1)
Me too i didn't use the Arduino but only the ATMEGA and of course what it takes to make it work. View photos of the card and you'll see that I put only the chip. The card is designed to connect directly to an Arduino (CN1) connecting the various pins but it is a choice. In this case you don't need C1-C2-X1-R1 because are already included in the Arduino. Greetings

ddolbi1 (author)Cello622011-11-18

Thanks for the quick reply.
What do you mean by I don't need C1-C2-X1-R1? Isn't the point having them so I can build the arduino on the card itself?
Also, I'm not very good with arduinos, but can I program the microcontroller on an arduino UNO, then take out the chip and just place it on the card?
Thanks again!

Cello62 (author)ddolbi12011-11-18

I hope to explain you well:
-if you use a board like the one i did, with a ATMega standalone, you need c1-c2 and so on, better you need capacitors, clock, resistor, all that is indicated by my scheme ok? If you plan to connect an Arduino to my board it is no necessary to add these component because are already included in an typical Arduino board, if you plan to build another board with an Atmega standalone to connect to my board you need all these component (and others like power supply and so on) but in your board to drive the Atmega ok? The last method is a no sense because is more simple to add an Atmega to my board.
For the second question YES, i have done this, i've buyed an Atmega 328 with bootloader inside, replaced with that of Arduino UNO, reprogrammed and placed on my board.

ddolbi1 (author)Cello622011-11-18

Wow. Thanks! That solved all my problems!

ddolbi1 (author)Cello622011-11-18

And also, I have a question regarding the CN3. I placed 3 male pins on it, and I'm confused about pin 1 and 3. What's going through those pins? It appears to me that there are no currents going through them because they are open.
If I'm mistaken, what else gets connected to these pins other than the microcontroller?

Cello62 (author)ddolbi12011-11-18

CN3 is for the two buttons that regulate the hours and minutes. Pin 1 is for one and Pin3 is for the other. Pin2 is for 5volt shared toghether.

HomelandSecurity (author)2011-11-08

If I could ask a couple of questions - how could I get a copy of that PCB board - also would a project like this be easy for someone with a basic understanding of circuits and various experiences soldering?

Cello62 (author)HomelandSecurity2011-11-08

Hi ty for reply. Methods may be different. I have given the schematic to a designer and i did make the PCB to a professional mastering there are several on the internet. You must send the gerber (software) file after you decide how many cards you want to achieve. Once you have the card is very easy to solder the components. As i wrote in the instructions i sell the gerber files, after you can choose where to make the pcb. To solder the components is very easy after looking the schematic. Regards

About This Instructable




More by Cello62:My Arduino Ping Display RobotMy Arduino Binary ClockMy Arduino WordClock
Add instructable to: