Not me? Just did some more or less useful stuff with my STK-500 dev boad. I took 64 leds and formed a 8×8 matrix out of them, solderd them onto 2 layers of ciruit boards. The leds are connected to 2 8Bit IO-Busses of an Atmel AT90S8515. I use one bus to select a row and the other bus to write on byte into a led-row. since iam changing the rows very quick, you won’t see an flicker. actually it’s 100hz refresh rate.
Then i a wrote a litte library in C using AVR-GCC to access the matrix like an framebuffer. Also funny stuff like scroll text is included in that lib. On top of this a wrote some code to interface the Atmel to PC’s serial port. That incoming data from the SIO get’s displayed on the led matrix.
So that an echo “\xFF” > /dev/ttyS0 on the linux box will light up one row of the led matrix.
Last but not least i took a XMMS template plugin. Reworte it so the level output of the vu-meter is cutted down to 8 values. These values get sent to the PC’s serial interface.that’s it.