Published September 5, 2024 © Apache-2.0

World's Smallest RGB LED Cube With 384 Pixels

Compact RGB LED Cube with 384 pixels in an 8cm³ design. Powered by ATmega328, WS2812B LEDs. Full tutorial from PCB to assembly.

IntermediateFull instructions provided24 hours1,662

World's Smallest RGB LED Cube With 384 Pixels

Things used in this project

Hardware components

Microchip ATmega328

Adafruit NeoPixel Ring: WS2812 5050 RGB LED

Rechargeable Battery, 3.7 V

JLCPCB Customized PCB

Software apps and online services

Arduino IDE

CircuitMaker by Altium Circuit Maker

Hand tools and fabrication machines

3D Printer (generic)

Hot Plate, Convection

Soldering iron (generic)

Solder Wire, Lead Free

Solder Paste, Rework

Story

Welcome to my tutorial on building what might be the world’s smallest RGB LED Cube! In this project, I’ll walk you through the entire process of designing and assembling an ultra-compact LED cube, containing 384 individual addressable RGB LEDs, packed into an 8 cubic centimeters layout. This cube is powered by an ATmega328 microcontroller and uses WS2812B LEDs, giving you endless possibilities for lighting effects and animations.

Whether you're a beginner or an experienced maker, this project will challenge your soldering skills and creativity. Follow along, and by the end of this guide, you’ll have your very own miniature RGB LED cube displaying vibrant animations.

Supplies

Here’s a list of everything you’ll need to build the cube:

Electronic Components:

ATmega328p microcontroller (SMD MLF version)
384 WS2812B-1010 RGB LEDs (1x1mm): Buy here
1.27mm SIL headers (for charging and ON/OFF)
3.7V lithium-ion battery: Buy here
SS14 Schottky diode
22pF ceramic capacitors (0402 package)
P-channel MOSFET
16MHz crystal oscillator

PCB and Soldering Materials:

Custom PCB (order from JLCPCB)
Solder paste: Buy here
PCB stencil
Flux remover solvent: Buy here
Hot plate (or reflow oven): Buy here

Tools and Software:

3D Printer: Buy here
Altium Designer (for circuit design)
Arduino IDE (for programming)
Soldering iron and core wire
Microscope for inspecting solder joints: Buy here
USB-C cable for programming: Buy here

Designing the Circuit Schematic

The core of this RGB Cube is the ATmega328p microcontroller paired with WS2812B-1010 addressable RGB LEDs. The ATmega328p was chosen for its Arduino compatibility and sufficient I/O capabilities, while the WS2812B LEDs allow for daisy-chaining control, requiring just one pin to handle all 384 LEDs.

Power and Circuit Design:

The cube is powered by a 3.7V lithium battery.
The ATmega328p runs at 5V with a 16MHz crystal oscillator for stable operation.

Using Altium Designer, I created a compact schematic, keeping trace lengths short and adding bypass capacitors to reduce noise. I also optimized power usage through code, ensuring the cube can handle vibrant animations without overloading the system.

Download the Schematic:

You can download the schematic here:

Designing and Manufacturing the PCB

With the schematic complete, it was time to move on to the PCB layout. The goal was to fit 384 tiny 1x1mm WS2812B LEDs onto an 8 cubic centimeter cube, so space optimization was key. Using Altium Designer, I carefully placed the components and routed the traces to ensure smooth data and power flow across the entire LED array.

PCB Design:

I created a 2-layer PCB to accommodate the high density of components while keeping the board compact.
To ensure reliable connections, I routed ground plane separately from the signal traces, reducing electrical noise.
The ATmega328p microcontroller was placed at the center, allowing short signal traces to all LED arrays.
I also added mounting pads for a 1.27mm pitch header to allow easy reprogramming and power connection.

Manufacturing:

Once the PCB design was finalized, I uploaded the Gerber files to JLCPCB, who handled the manufacturing. Their precision fabrication and affordable prices made them an excellent choice for a small, complex project like this.

After receiving the boards, I performed a quick inspection to ensure the traces and solder mask were clean and accurate. Everything looked perfect, so I was ready to move on to assembling the components.

Download the PCB Design:

You can download the Gerber files here:

Download Gerber Files

Soldering the LEDs and Components

For this project, I used a hot plate to reflow the solder paste and attach the LEDs and components. These 1x1mm WS2812B LEDs are incredibly small, so using the stencil was essential for applying solder paste evenly.

Here’s a detailed guide on handling these tiny components and ensuring a solid connection:

Use fine-tipped tweezers for placing LEDs.
A microscope will help with inspecting your solder joints.
A flux remover will help clean up any excess solder and ensure clean connections.

If you prefer soldering by hand, then you can only solder the bottom side components, as for the LEDs it is not possible to solder them by hand.

Programming the LED Cube

With the hardware complete, it’s time to program the cube. The ATmega328 microcontroller runs the show, and I programmed it using the Arduino IDE. The code drives animations across the 384 LEDs, creating dynamic light patterns.

You can download the Arduino code I used from the link below. Feel free to modify it or create your custom animations!

Download Arduino Code

Programming Tips:

You’ll need to burn the bootloader onto the ATmega328p.
To program, I used a simple ISP programming technique, which you can learn about here.

Assembling the Cube and Final Testing

The final step is assembling the cube. I 3D printed a simple assembly aid to hold the LED layers in place while soldering them together. Once the cube was fully assembled, I tested it to ensure all LEDs functioned properly and that the animations displayed as expected.

Download Cube Assembly aid STL File

I encountered a few challenges along the way, mainly with aligning the LEDs matrices perfectly, but once completed, the results were incredible. You now have a tiny RGB LED cube capable of displaying beautiful, vibrant animations!

Final Thoughts

This tiny RGB LED cube project is both a fun and rewarding challenge. Whether you’re new to electronics or a seasoned hobbyist, it’s a great way to practice fine soldering skills, PCB design, and power management for small-scale electronics. Plus, the end result is a mesmerizing cube full of vibrant color animations!

I hope this tutorial helps you in your journey to create your LED cube. Don’t forget to share your thoughts, ask questions, and show off your creations in the comments below!

Useful Links:

Custom parts and enclosures

Sketchfab still processing.

Schematics

Code

Arduino code

#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
  #include <avr/power.h>
#endif
#define PIN            7
#define NUMPIXELS      384

int Red=0;
int Green=0;
int Blue=0;
Adafruit_NeoPixel MyCube = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);


void setup()
{
  MyCube.begin();
  MyCube.setBrightness(10);
  delay(1000);
  for(int j=0; j<100; j++)
  {
    MyCube.setBrightness(j);
    for(int k=0;k<NUMPIXELS;k++)
    {
      MyCube.setPixelColor(k,MyCube.Color(255,30,30));
    }
    MyCube.show();
    delay(1);
  }
  for(int j=100; j>=0; j--)
  {
    MyCube.setBrightness(j);
    for(int k=0;k<NUMPIXELS;k++)
    {
      MyCube.setPixelColor(k,MyCube.Color(255,30,30));
    }
    MyCube.show();
    delay(1);
  }
}

void loop()
{
  MyCube.setBrightness(50);
  discoMode(5);
  MyCube.setBrightness(15);
  glowLightRandom(1);
  delay(random(300,7000));
  randomLightShow(500);
  delay(random(500,8000));
  slideMoveFast(1);
  delay(random(700,3000));
  smoothColorShow(1);
  delay(500);
  
  Red=random(0,255);
  Green=random(0,80);
  Blue=random(0,50);
  for(int j=0; j<100; j++)
  {
    MyCube.setBrightness(j);
    for(int k=0;k<NUMPIXELS;k++)
    {
      MyCube.setPixelColor(k,MyCube.Color(Red,Green,Blue));
    }
    MyCube.show();
    delay(1);
  }
  for(int j=100; j>=0; j--)
  {
    MyCube.setBrightness(j);
    for(int k=0;k<NUMPIXELS;k++)
    {
      MyCube.setPixelColor(k,MyCube.Color(Red,Green,Blue));
    }
    MyCube.show();
    delay(1);
  }
}

void discoMode(int repeat)
{
  for(int i=0; i<repeat ; i++)
  {
    int colorSetRed=random(0,255)/32;
    int colorSetGreen=random(0,255)/32;
    int colorSetBlue=random(0,255)/32;
    int brightnessRed=colorSetRed*5;
    int brightnessGreen=colorSetGreen*5;
    int brightnessBlue=colorSetBlue*5;
    for(int j=0 ; j<30 ; j++)
    {
      int firstPixel=random(0,128);
      for(int i=0; i<3 ; i++)
      {
        for(int k=0;k<NUMPIXELS;k++)
        {
          MyCube.setPixelColor(k,MyCube.Color(colorSetRed,colorSetGreen,colorSetBlue));
        }
        delay(1);
        MyCube.show();
        MyCube.setPixelColor(firstPixel,MyCube.Color(brightnessRed,brightnessGreen,brightnessBlue));
        delay(1);
        MyCube.show();
        MyCube.setPixelColor(firstPixel,MyCube.Color(colorSetRed,colorSetGreen,colorSetBlue));
        delay(1);
        MyCube.show();
      }
    }
  }
}
void smoothColorShow (int repeat)
{
  for(int k=0 ; k<repeat ; k++)
  {
    for(int j=255; j>=0; j--)
    {
      for(int i=0;i<NUMPIXELS;i++)
      {
        MyCube.setPixelColor(i,MyCube.Color(0,255,j));
      }
      delay(3);
      MyCube.show();
    }
    for(int j=0; j<256; j++)
    {
      for(int i=0;i<NUMPIXELS;i++)
      {
        MyCube.setPixelColor(i,MyCube.Color(j,255,0));
      }
      delay(3);
      MyCube.show();
    }
    for(int j=255; j>=0; j--)
    {
      for(int i=0;i<NUMPIXELS;i++)
      {
        MyCube.setPixelColor(i,MyCube.Color(255,j,0));
      }
      delay(3);
      MyCube.show();
    }
    for(int j=0; j<256; j++)
    {
      for(int i=0;i<NUMPIXELS;i++)
      {
        MyCube.setPixelColor(i,MyCube.Color(255,0,j));
      }
      delay(3);
      MyCube.show();
    }
    for(int j=255; j>=0; j--)
    {
      for(int i=0;i<NUMPIXELS;i++)
      {
        MyCube.setPixelColor(i,MyCube.Color(j,0,255));
      }
      delay(3);
      MyCube.show();
    }
    for(int j=0; j<256; j++)
    {
      for(int i=0;i<NUMPIXELS;i++)
      {
        MyCube.setPixelColor(i,MyCube.Color(0,j,255));
      }
      delay(3);
      MyCube.show();
    }
  }
}

void slideMoveFast(int repeat)
{
  for(int i=0;i<NUMPIXELS;i++)
  {
    MyCube.setPixelColor(i,MyCube.Color(0,0,0));
  }
  MyCube.show();
  for(int i=0 ; i<repeat ; i++)
  {
    for(int i=0;i<NUMPIXELS;i++)
    {
      MyCube.setPixelColor(i,MyCube.Color(random(0,255),random(0,255),random(0,255)));
      delayMicroseconds(10);
      MyCube.show();
    }
    
    for(int i=0;i<NUMPIXELS;i++)
    {
      MyCube.setPixelColor(i,MyCube.Color(0,0,0));
      delayMicroseconds(10);
      MyCube.show();
    }
  }
}

void glowLightRandom(int repeat)
{
  int glowRed=0;
  int glowGreen=0;
  int glowBlue=0;
  for(int i=0 ; i<repeat ; i++)
  {
    int Red=random(0,255);
    int Green=random(0,255);
    int Blue=random(0,255);
    for(int i=0; i<255; i++)
    {
      for(int j=0; j<NUMPIXELS; j++)
      {
        MyCube.setPixelColor(j,MyCube.Color(glowRed,glowGreen,i));
      }
      MyCube.show();
      delay(1);
      if(glowRed<Red)
      glowRed++;
      if(glowGreen<Green)
      glowGreen++;
    }
    for(int i=255; i>=0; i--)
    {
      for(int j=0; j<NUMPIXELS; j++)
      {
        MyCube.setPixelColor(j,MyCube.Color(glowRed,glowGreen,i));
      }
      MyCube.show();
      delay(1);
      if(glowRed>0)
      glowRed--;
      if(glowGreen>0)
      glowGreen--;
    }
    Red=random(0,255);
    Blue=random(0,255);
    for(int i=0; i<255; i++)
    {
      for(int j=0; j<NUMPIXELS; j++)
      {
        MyCube.setPixelColor(j,MyCube.Color(glowRed,i,glowBlue));
      }
      MyCube.show();
      delay(1);
      if(glowRed<Red)
      glowRed++;
      if(glowBlue<Blue)
      glowBlue++;
    }
    for(int i=255; i>=0; i--)
    {
      for(int j=0; j<NUMPIXELS; j++)
      {
        MyCube.setPixelColor(j,MyCube.Color(glowRed,i,glowBlue));
      }
      MyCube.show();
      delay(1);
      if(glowRed>0)
      glowRed--;
      if(glowBlue>0)
      glowBlue--;
    }
     Green=random(0,255);
     Blue=random(0,255);
    for(int i=0; i<255; i++)
    {
      for(int j=0; j<NUMPIXELS; j++)
      {
        MyCube.setPixelColor(j,MyCube.Color(i,glowGreen,glowBlue));
      }
      MyCube.show();
      delay(1);
      if(glowGreen<Green)
      glowGreen++;
      if(glowBlue<Blue)
      glowBlue++;
    }
    for(int i=255; i>=0; i--)
    {
      for(int j=0; j<NUMPIXELS; j++)
      {
        MyCube.setPixelColor(j,MyCube.Color(i,glowGreen,glowBlue));
      }
      MyCube.show();
      delay(1);
      if(glowGreen>0)
      glowGreen--;
      if(glowBlue>0)
      glowBlue--;
    }
  }
}

void randomLightShow(int repeat)
{
  for(int i=0; i<repeat ; i++)
  {
    int firstPixel=random(0,384);
    MyCube.setPixelColor(firstPixel,MyCube.Color(random(0,255),random(0,255),random(0,255)));
    delay(1);
    MyCube.show();
    MyCube.setPixelColor(firstPixel,MyCube.Color(0,0,0));
    delay(1);
    MyCube.show();
  }
}

Credits

DIY GUY Chris

51 projects • 342 followers

I'm having fun while making electronics projects, I am an electrical engineer in love with "Do It Yourself" tasks.

World's Smallest RGB LED Cube With 384 Pixels

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Supplies

Electronic Components:

PCB and Soldering Materials:

Tools and Software:

Designing the Circuit Schematic

Power and Circuit Design:

Download the Schematic:

Designing and Manufacturing the PCB

PCB Design:

Manufacturing:

Download the PCB Design:

Soldering the LEDs and Components

Programming the LED Cube

Assembling the Cube and Final Testing

Final Thoughts

Useful Links:

Custom parts and enclosures

Cube assembly aid

Schematics

Schematic

Code

Arduino code

Credits

DIY GUY Chris

Comments

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World's Smallest RGB LED Cube With 384 Pixels

World's Smallest RGB LED Cube With 384 Pixels

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Supplies

Electronic Components:

PCB and Soldering Materials:

Tools and Software:

Designing the Circuit Schematic

Power and Circuit Design:

Download the Schematic:

Designing and Manufacturing the PCB

PCB Design:

Manufacturing:

Download the PCB Design:

​Soldering the LEDs and Components

Programming the LED Cube

Assembling the Cube and Final Testing

Final Thoughts

Useful Links:

Custom parts and enclosures

Cube assembly aid

Schematics

Schematic

Code

Arduino code

Credits

DIY GUY Chris

Comments

Related channels and tags

Soldering the LEDs and Components