Matt Meerian's Fireworks Animation on a 5x7 LED Display

This is small project that shows an animation of a fireworks rocket going off a 5x7 LED dot matrix array. The microcontroller used is an ATMEGA32 from Atmel. A much smaller microcontroller could have been used, but the ATMEGA32 was already on the solderless breadboard and the ATMEGA32 also has great debugging capabilities through the J-tag header.
The red LED array module is part number LDM-07457NI, from Lumex. Any LED array that has an X-Y configuration could be used. The microcontroller steps through the LED matrix lighting one row at a time. Since the row lighting is done very quickly, it looks like more than one row is lit at a time. Five, 2N3904 NPN transistors were used to boost the current handling capabilities of the I/O pins on the microcontroller.
The inspiration for building this circuit was an LED sign seen at a wedding in November of 2005. Obviously, the LED sign had a much larger LED matrix and was brighter. Anyway, the fireworks animation on the sign was very eye catching.
A schematic, source code, and a photo of the circuit on a solderless breadboard are included. A permanent circuit board was not built since the circuit is more of curiosity than a practical circuit.