For this Halloween, I'm fusing the creative blocky world of Minecraft with the spooky glow of the colorful RGB LEDs in a fun and simple Halloween project. A "Color Adjustable Minecraft Lantern" is a project that recreates the iconic lantern from the video game Minecraft. It allows the user to change the light's color to any hue, rather than being limited to the standard yellow or orange glow. 

Video: https://www.youtube.com/watch?v=8wauoKaCeak

Components Required

For this project we need:

•   [Buy Now] 1 x Arduino Nano
•   [Buy Now] 2 x WS2812B 16 LEDs NeoPixel Ring
•   [Buy Now] 4 x 10kΩ Rotary Potentiometer
•   [Buy Now] 1 x 1000µF capacitor is highly recommended to smooth out voltage spikes and dips
•   [Buy Now] 1 x 100Ω Resistor placed in series on the data line to limit the current and dampen signal reflections
•   [Buy Now] 1 x SPST Switch
•   [Buy Now] 1 x 18650 Battery and a Holder
•   [Buy Now] 1 x TP4056 Battery Charging Module
•   [Buy Now] 1 x DC-to-DC Buck Converter
•   Jumper Wires & Breadboard
•   and a 3D printer to print the enclosure

Wiring Diagram

The setup consists of three simple circuits:
1. First, the power circuit: a battery that charges and runs the Arduino Nano
2. Second, the control circuit: a potentiometer feeding signal to the Arduino
3. And third, the light circuit: the NeoPixels, which lights up based on the instructions received from the Arduino 

Explanation of operation:
The Arduino reads the potentiometers via its analog pins, generating values from 0 to 1023. This range is then mapped to 0-255 to comply with the Arduino library. The converted signal is then sent sequentially to the LEDs, lighting them up one by one from first to the last.

Two key components are required for signal integrity: a 1000µF capacitor closest to the load to stabilize the voltage, and a 100Ω resistor on the data line to protect against current surges and dampen signal noise.

[[In general, caps are for 3 things. To provide a reservoir of current to keep voltage stable, to bypass noise to ground and to pass AC signals while blocking DC. The third is of no use in this context, but the other 2 are. Higher value caps are used as reservoirs (ie.1000uF) and lower values to bypass noise (0.1uF, 1uF). As a rule of thumb, caps should be placed close to where the problem that they are to solve occurs]]

The Code

The code begins by including the Adafruit NeoPixel library and by defining the necessary pins and global variables.

In the setup() section, we initialize the NeoPixel library and immediately run a rainbow cycle across the entire LED ring to confirm it's working.

The loop() section continuously reads the potentiometer value, mapping it from a 0-1023 range to 0-255. You'll notice that I commented out the brightness control section. This is because, during my testing, I found that the NeoPixel library's brightness setting proportionally scales all RGB values, which significantly alters the LEDs' perceived color and intensity.

Important Considerations
  Color Perception: Lower brightness can make colors appear different than expected
  Power Consumption: Lower brightness = less power used
  Heat Generation: Lower brightness reduces heat
  Eye Comfort: Very bright NeoPixels can be uncomfortable to look at

Finally, the code uses the mapped potentiometer values to set the pixel colors and updates the LED display. This creates a direct, real-time control between the potentiometers and the LED output.

Breadboard Testing

Before putting everything into the enclosure, I hooked them up on a breadboard to test the code. When I power it on, you can see the NeoPixel rings plays a little rainbow animation, and then they are ready to go. Now, when I turn these knobs, the colors change smoothly as the Arduino reads the potentiometer values and updates the LEDs in real-time.

3D Design

I designed a custom 6-part...