The idea is to control a RGB LED matrix with a PC using Java and Bluetooth. I'm using the HC-06 Bluetooth module to establish a Bluetooth connection. This module works like a wireless RS232 interface. It is connected to a ATTiny2313's UART periphery.

I wrote a small Java program, which connects to the COM port of the Bluetooth module, to send small ASCII commands to control the color of each LED.

The idea is to connect more 2x2 LED modules to one big 10x10 LED matrix. LED drivers a more expensive than a ATTiny2313 (~1-2$ ea), that's why I'll use one µC for 4 RGB LEDs (4*3 LEDs). The brightness is very high due to no need of multiplexing.

Figure 1: Eagle schematic

This is a small video of the first approach. The software is working for one 2x2 module and will be improved to handle the whole 10x10 matrix. I'm planing to add some animations presets (e.g. clock, spectrum of music played in WinAmp/foobar200, mail notification)

...and now in the dark

Two new videos from the working prototype.

Prototype 2.0, now with separators made of cardboard between the LEDs.

This is the first prototype board.

Figure 2: First prototype board

First in test at night :)

Figure 3: Light me up, before you gogo

First function test with frame and front screen.

Figure 4: Function test

Finally, all 25 modules are cut out and the parts are placed...some of the roots are missing.

Figure 5: 25...soldering is fun

Figure 6: All modules connected and placed

Figure 7: Front view

Figure 8: First test with #ff00ff

Figure 9: Closeup

Figure 10: Working prototype (Windows image) 1

Figure 11: Working prototype (Windows image) 2

Figure 12: Separator made of cardboard

Figure 13: Frame is now divided into 100 pieces

Figure 14: Ready for the next test

Figure 15: Separator test (1)

Figure 16: Separator test (2)

Figure 17: Separator test (3)

Figure 18: Separator test (4)