Smouldering-Dog writes – “This is from my site. It describes construction of a simple microcontroller circuit that has user I/O, two seven segment LEDs, a buzzer and A/D converter. It was originally made to drive a CO2 laser but the new firmware can be installed on the microcontroller to program the board to perform other functions. Readers might be interested to see how easy it is to design and manufacture a custom printed circuit board.” Link.