My Arduino WordClock




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Step 1: 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

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

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

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

Step 5: 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

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

Step 7: 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

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

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

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

Step 11: 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

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

Step 14: 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.

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    60 Discussions


    Question 9 months ago on Step 12

    Hello. I like your version of the word clock.
    Is the gerber file still available?


    1 year ago

    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

    2 replies

    Reply 1 year ago

    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.


    4 years ago on Step 15

    The Arduino code produces errors when compiling.

    What is wrong?



    4 years ago on Introduction

    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 .... ^_^

    1 reply

    Reply 4 years ago on Introduction

    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.


    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!

    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.


    1 reply

    5 years ago

    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?


    1 reply

    Reply 5 years ago on Introduction

    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


    Reply 5 years ago

    I don't find the source code :-(


    5 years ago on Introduction

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


    6 years ago on Introduction

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