4x4x4 NeoPixel LED Cube

Overview

Designed and built a fully functional 4x4x4 interactive LED display system combining hardware construction and embedded software. The cube uses 64 WS2812B NeoPixel LEDs soldered onto a custom copper wire frame built layer by layer using a precision jig to maintain consistent spacing and alignment. Each of the four layers was continuity-tested before stacking and the complete assembly was housed inside a custom wooden enclosure with access ports for USB programming and power input.

The firmware runs on an Arduino Uno (ATmega328P at 16 MHz) and implements a non-blocking state machine using millis() to manage four independent animation modes without blocking the input polling loop. Mode 0 runs a colour wipe cascading through red, green and blue. Mode 1 smoothly fades all LEDs through the RGB spectrum simultaneously. Mode 2 simulates a fire effect using a per-LED heat value algorithm that maps temperature to colour from deep red through orange to bright yellow-white. Mode 3 cycles a full rainbow gradient across the array using a hue-wheel algorithm.

An LDR sensor on pin A0 reads ambient light at 10-bit resolution (0-1023) and maps it inversely to LED brightness (20-255) so the cube dims automatically in bright environments to reduce eye strain. A debounced power button on D2 toggles the system on and off with buzzer confirmation, and a mode button on D3 steps through the animation patterns. A 1000 µF electrolytic capacitor on the 5V rail stabilises voltage during rapid LED switching. The firmware streams live diagnostic data over serial at 9600 baud including LDR readings, calculated brightness values and active pattern name.

Key highlights

• ·64 WS2812B LEDs hand-soldered onto a custom copper wire frame built layer by layer
• ·Non-blocking state machine using millis() keeps input polling running during all animations
• ·Four animation modes: colour wipe, smooth RGB fade, fire effect and rainbow cycle
• ·LDR adaptive brightness - maps 10-bit ambient light reading to 8-bit LED intensity in real time
• ·Debounced button inputs for power toggle and mode cycling with buzzer feedback
• ·1000 µF decoupling capacitor on the 5V rail protects LEDs from switching voltage spikes
• ·Live serial diagnostic output at 9600 baud: LDR value, brightness level and active pattern
• ·Custom wooden enclosure with cable management, ventilation and front-panel controls

Technologies