The LED cube has 64 LEDs in a 4 x 4 x 4 matrix (see
Figure 3). There are four LEDs across the length, width, and
height. Each of the four layers contain 16 LEDs. Physical
dimensions are approximately 2. 5” x 2. 5” x 2. 5”, with
consecutive LEDs separated by 3/4”.
The LEDs are round and
measure 5 mm (T1-3/4) (see
Figure 4). Rectangular/oval
shaped LEDs can be used, but
may be a problem to hold
during construction. A diffused
lens will give you a wider viewing angle, especially for side
viewing, so keep these things in mind if you’re purchasing
your own LEDs. For the kit, we purchase super bright clear
LEDs and sand blast them ourselvs to diffuse the lens. LED
leads should be 1” long and are used to connect
consecutive LEDs (which are 0.75 “ apart).
Figure 4. LED, showing
lengths of the cathode and
Figure 3. LED matrix ( 4 x 4 x 4).
Figure 5. LED cube schematic.
Cube connection 16 x 4 multiplexed, common anode.
R17 to R20 value 220 ohms, quarter watt.
For 12 mA current through each LED.
R1 to R16 values dependent on LED color used, 150 ohms quarter watt for 3V forward LED drop.
August 2011 45