Watch a 4x6 - Matrix on YouTube:
This thing is a LED-Matrix ... the Cubes are 8cm x 8cm x 3cm .. the Chip for controlling the LED's is a WS2803 (get them at ebay) .. a WS2803 is a constant-current-led-driver with 18 channels .. meaning with 1 chip you can control 18 leds or 6 rgb leds.
Please note a RGB-LED is having different voltages per color ... but the same current ;-) .. so a constant current driver will ensure the voltages are automatically set by the chip .. you dont have to care about that.
Okay .. this tiny Chips are SPI-Controller ... so they have a Input-CLOCK-Pin and Input-DATA -Pin ... AND best of all ;-) Clock-Out-Pin and Data-Out-Pin .. so you can chain this chip with 2 wires :-)
e.g. for the 15 x 6 RGB-LED-Matrix i'am building .. a build 6 Cube-Columns ... every column is powered by one WS2803 Chip which is connected to the next column .. its quite easy to build a giant LED-Matrix with this driver .. please notice .. a LED is max. requiring 20ma so in my scenario i'am using 15*6 Leds => 90 LEDs each LED will require current ;-) so you need a pretty strong power-source (5v @ 6a)
For controlling the WS2803 i'am using a simple Arduino UNO (you can use any other microcontroller you like .. Picunio .. stm32...)
At the Bottom of every column i am mounting a "electronics cube" for the ws2803 circuit .. the cubes are having wiring holes ... one led-mount (you need cooling to get the correct diameter) and a option to use cable ties .... i used a glue gun.
*** For the WS2803 you ned RGB-LEDs with same ANODE (+) ***
*** The WS2803 is a PWM-Driver so you can dim every led with 8 bit (0..255) ***
*** The photos are showing the back-side of the cubes ;-)
*** Power-Source Notes:
LED[r?] 2,2v * 20ma => 0,044 Watt per Channel
LED[g?] 3,3v * 20ma => 0,066 Watt per Channel
LED[b?] 3,4v * 20ma => 0,068 Watt per Channel
LED => 0,79 Watt per LED
e.g. 6x6 Matrix => 36 RGB-LEDs (108 Channels)
36 RGB-LEDs * 0,79W => 28,44 Watt + ICs + Microcontroller + Doubled-Security ..
Lets say a 60 Watt Power-Source should be fine in this case .. however .. do our own calculations ;-) ..