LED matrix message displays are really cool. Here is one based on PIC microcontroller that displays time, calendar, temperatures, and, text messages. It can store for up to 10 messages, each 250 characters long, and supports both static and running messages. Message selection can be done through an IR remote control. The brain of this device is a PIC18F252 microcontroller and uses 16-bit serial-in-parallel-out shift registers to drive the LED columns. It operates with 12-24 V DC power supply.