New project: Wordclock

For some time now I was intrigued by wordclocks. Sadly, all clocks I found so far are quite pricy, so I decided to build my own, using an Arduino for the electronics. The clock is going to be a gift, so I’m going to keep these posts private until the gift is given, so all related posts are going to appear at once.

Yesterday I ordered the first parts for the project, an Arduino Mega 2560 along with a set of white LEDs. Originally I wanted to use an Arduino Nano, but while I was doing the concrete planning of the electronics I realized that would mean quite an excessive amount of soldering on my part. The Nano has only 14 digital pins, but for a minimal german word clock I need to control 19 individual lights, I’ll have 21. My first idea to use a logic gate fell short when I calculated the logic gate.

es ist fünf zehn viertel
zwanzig  nach  vor  halb
eins zwei drei vier fünf
sechs sieben  acht  neun
zehn   elf   zwölf   uhr

There are just too many things that can go wrong here, additionally this would be using quite an amount of space. So I’m going for the Arduino Mega, which has 54 digital pins. A little excessive, but way easier to build. I’m going to add an DCF77 radio clock module so I won’t have to bother with the functions to set the time. The module will reduce the available pins on the Arduino further when it’s connected. Integrating it shouldn’t be too hard, a library to access it from an Arduino already exists.

This is how I want to build it: The top is going to be a layer of acrylic glass, with the words being cut out somehow. I’m not sure yet how I’m going to do this, I have a couple of ideas to try. Below that I want to use a layer of diffuse acrylic, to spread the light from the LEDs more evenly. Maybe I can merge these two layes, I’ll have to try it.

Things to figure out: how to separate the LEDs from each other, how to build the case (probably thin PVC). But first things first, I’ll have to wait for the first parts to arrive. Then I’ll start playing with them.