I've decided to use one of those RGB LED with build in driver. The choice has been done for popular WS2812B, which I had been use in one of my previous project (ArduSHIELD https://hackaday.io/project/9086-ardushield-most-hacker-shield-for-arduino).

I used library called FastLED. This library has wide variety of function and it is really easy to use and it has support for Arduino.

There are 22 LEDs in one chain. For driving all the LEDs in chain I used Arduino Nano board, there is a plan to move  to ATtiny85 in final version. I just take Arduino Nano in case of easy start with Arduino IDE.

Here are the example of 12H period of time compressed in just one minute.


There are 12 levels of brightness depend where the clock is standing. In the night you would rather use level ONE or TWO, other way is is quite bright. In the sunny day level NINE or TEN is sufficient.

Counting the time is done by PCF8563T.

To sustain time when Word Clock is disconnected from power supply I used supercapacitors. Supercapacitor has 0,22F@5V5.

Time for full charge backup capacitors is about 15-20 minutes . After full charge Word Clock can sustain memory of time around 5-7 days.

60 seconds

Showing seconds by combination of sum of following names (numbers) on the Word Clock

Mode controle

Playing with Word Clock is done by one switch.

Thera is main loop with 5 functions like a Time, Seconds, Mode, Brightness and Colour.
By short click aroud 0.2-0.4 sec. you go through maing loop.
If you hold on button for longer time around 1 sec. then you will go in to specyfic settings.
Then again you can use short click to go through specyfic settings. If you chouse desire mode then finish by holding the  button one more time for about 1 sec and you will back to main loop.

Micro USB power supply

Word Clock is supplied with standard micro USB connector. You can use any phone charger with current around 1.5A when you runn clock with full brightness with all LEDs. Each LED draw 60mA max.

Just few photos in the night with different layout of word clock.

and not only the words