4x4x4 LED Cube with Arduino and Shift Registers

An LED cube is the rite-of-passage electronics build for a reason: it forces the student to do everything at once — solder 64 LEDs into a mechanically sound 3D frame, drive them with far fewer microcontroller pins than LEDs through multiplexing and shift registers, and write animation code in three dimensions. The engineering core is layered multiplexing: only one of the four layers is powered at a time, cycling fast enough that persistence of vision shows a complete 3D image, while two 74HC595 shift registers select which of the 16 columns in the active layer light up. This project delivers that full build — a hand-soldered 4x4x4 cube on a wooden base, transistor-driven layers, shift-register column drivers, and a firmware library of 3D patterns from rain and plane-sweeps to expanding spheres.

1. The 64 LEDs are soldered as 4 layers of 4x4 grids; all anodes in a vertical column are joined, and all cathodes in a layer are joined.
2. Two cascaded 74HC595 shift registers drive the 16 column lines through current-limiting resistors.
3. Four NPN transistors (or a ULN2803) sink the layer cathodes, enabling one layer at a time.
4. Firmware shifts out the 16-bit column pattern for the active layer, enables that layer's transistor for a short slice, then moves to the next layer.
5. Cycling all four layers faster than the eye can follow renders a stable 3D image by persistence of vision.
6. The animation engine updates a 4x4x4 frame buffer in 3D coordinates and pushes it to the multiplexing routine each frame.

Tech stack:

• Arduino Uno (ATmega328P)
• 64 × 5 mm LEDs (single colour)
• 2 × 74HC595 shift registers (cascaded)
• NPN transistors / ULN2803 for layer drive
• Wooden base, resistors, push button, speed potentiometer
• 5 V regulated power supply
• Arduino IDE (C/C++ firmware)

• [Hand-soldered 4x4x4 grid] 64 LEDs soldered into a rigid 3D frame on a wooden base — the craftsmanship of the build is part of the deliverable.
• [74HC595 shift-register drive] Two cascaded shift registers select the 16 columns using only 3 Arduino pins, demonstrating serial-to-parallel expansion.
• [Layered multiplexing] Four transistor-driven layers switch in rapid sequence; persistence of vision renders the full 3D image from one active layer at a time.
• [3D animation library] Firmware includes coded patterns — rain, plane sweeps, expanding/contracting cube, random sparkles — each written as 3D frame logic.
• [Pattern speed control] A potentiometer adjusts animation speed live, and a push button cycles through the pattern set.
• [Current-limited design] Series resistors and transistor layer drivers keep every LED within its rated current; the design targets standard 20 mA operation.
• [Extensible frame code] The animation engine exposes a simple set-voxel API so the student can code and demonstrate their own pattern.

• Hand-soldered 4x4x4 LED cube on wooden base
• Driver electronics (shift registers, layer transistors, controls)
• Arduino with animation firmware and pattern library
• 5 V power supply
• Soldering/assembly guide and wiring diagrams
• Project report PDF (multiplexing, shift registers, POV, pattern math)
• PPT presentation for final review
• Viva Q&A preparation document

• Single-colour LEDs only — RGB would need three times the drivers and is listed as future scope.
• 4x4x4 is the practical hand-soldered size; an 8x8x8 cube needs 512 LEDs and a different driver architecture.
• Brightness is multiplexed (each LED is on 1/4 of the time), so the cube suits indoor demo lighting, not daylight visibility.
• Soldering quality determines mechanical strength; the assembly guide documents the jig technique used.
• The pattern set is coded in firmware — adding new patterns needs a code change and re-upload, documented in the guide.