The purpose of this project is to make a LED cube using a minimum amount of pins from the microcontroller. An Arduino Nano (clone) used for the Atmega328p chip as the microcontroller, and a USBASP is used for programming. An example serial test program is available here.

The main code starts in LED_Cube4.c. The LED_Defaults.h file contains macros and variables used in both files. The LED_Effects.c contains the code for the animations.

There are three testing programs in the tests folder.

The 74HC595_Test program is for testing out the 74HC595 chips, and uses LEDs directly from each output of the chip. There is an included schematic for wiring.

The LED_Test tests each layer of the cube individually to be able to check the wiring of the LEDs. The Timer_Test is a simple test for the timing aspect of the code, along with having different presets for the FPS of the cube.

For the physical hardware, blue and green LEDs were used due to a shortage of green LEDs. This also created the pattern shown in the gif below where each corner and the middle LEDs are blue, with the rest being green.

It is highly suggested to test each LED before soldering, and to also use a jig (see right). This helps with placement of the image and also allows the structure to be layered on top of another. The jig was made by measuring the cathode (-) part of each LED, and finding that distance. Each cathode leg was then bent, and formed into a grid like pattern with 4 rows and two crossbeams on either end. The anodes are then connected together, with there being 16 inputs.

Top layer example: (middle layers use blue (b) in center instead of green (g)).

 Top layer:     Layer grid:     Side view:
 b--g--g--b     0  4  8  12     3 b--g--g--b
 |  |  |  |                       |  |  |  |
 g  g  g  g     1  5  9  13     2 g--g--g--g
 |  |  |  |                       |  |  |  |
 g  g  g  g     2  6  10 14     1 g--g--g--g
 |  |  |  |                       |  |  |  |
 b--g--g--b     3  7  11 15     0 b--g--g--b

A schematic is also available here.

The 4x4x4 cube by chr.
74HC595 shift register tutorial by Protostack.
74HC595 capacitor and resistor setup by Nerd Ralph.