Kaddu Klock is a little Arduino/Atmel based clock project. It is being prototyped using an Arduino Nano clone but should work with both the Arduino Uno and Mega platforms and their derivativs.
In the long run I plan to make this into a multi-coloured LED matrix display clock, possibly with Internet and Radio control connectivity.
The earliest prototypes were done with 7 segments (x 6) on a solderless breadboard:
After that I tried using 8x8 LED Matrices, again on a solderless breadboard:
The design is centered around the Atmel based Arduino, and a series of SN74HC595's to control the LEDs. There might be other ICs more suited to control LEDs, inkluding the MAX7219/7221 chips, but I had some 595's available. Also in the future, I plan to build a two-colour LED Matrix based display, where I cannot use the MAX7219/7221 chips as I have to control two colour LEDs per pixel while havin a common cathode. An different option for the 595's might be the Texas Instruments TLC5926/5927. I will look into that at a later stage.
Currently I am building the first prototype on Veroboard - the first more permanent prototype.