Running LED Bicolor
This is a good project for beginners. It is easy to build.This running LED light uses seven bicolor led's red and yellow, they light up in a pattern that can be made within the program code.The program code is written in assembler. ATMELs AVR STUDIO is used to write the program.
The project uses the AT1200 but the AT2313 can also be used. As a clock source a 4Mhz ceramic resonator is used, this is cheaper than a crystal. The board has to be powered with 5V DC.
Because each I/O port of the AT2313 can draw 20mA current, each I/O port can drive a LED. The LED's are connected to the port B and port D of the AT2313. By connecting one end of the LED to port B and the other end of the LED the port D the polarity of the LED can be reversed. By putting a 1 on port B and a 0 on port D, the LED will go red. By putting a 0 on port B and a 1 on port D, the LED will go yellow. Now by writing sequently different bytes to the port B and port D, you can create different patterns in which the LED's will light up.
Schematic and PCB Layout
The software is written in assembler code and can be downloaded below.