A while ago I attended an Arduino class from FabLab Zurich. The class included an Arduino starter pack with some fun modules from AdaFruit like this 8x8 bicolor LED square pixel matrix, a buzzer and some push buttons. I thought I could use them to build our new timer. Sounded like fun at first, then I found out it really is :)
I first followed this video tutorial to build a custom shield, since I didn't want to solder the parts directly to the Arduino board. Before laying out the components, I tested the circuit on a breadboard:
I then proceeded to solder the parts on the shield; it was a good exercise since I'm not very skilled:
Here's the side view, where you can see the offset of the digital pins header, a design flaw of the Arduino UNO mentioned in the video tutorial or in this forum:
Finally, the front view where you can see the LED matrix, two push buttons and the buzzer:
The software for the countdown timer is hosted on github. It works like this: each participant has 64 seconds for his turn. Each second, a pixel lights up. At 2 thirds of the time, the pixels turn yellow. The last 8 pixels, the LEDs are red, indicating that you should conclude. The way the pixels light up is random for each turn. At the moment, there are 3 variants:
- a simple row traverser
- a random pixel filler
- a spiral