Build a 7×7 monochrome LED display
Here is the circuit schematic as well as build instructions and parts list for an easy to build 7×7 LED matrix.
The 7×7 monochrome LED display comes into its own when showing animations. The link shows the circuit schematic is quite simple. All you need is an AVR, a few transistors, com resistors and some logic to convert RS232 to TTL.
Tags: led display, led matrix, logic, resistors, transistors