Michelle
Published

A "Tree of Light" Prototype

A "Tree of Light" with 9 plexiglass discs each adorned with LEDs arranged in a flower shape.

BeginnerShowcase (no instructions)250

Things used in this project

Hardware components

Espressif ESP32-WROVER-E
×1
WS2812B LED Strip 16.4ft 300 LED Pixel
×5
5V 60A 300W Power Supply
×1
ESP32 Terminal Block
×1
22 gauge wire
I had this leftover from a past project, and I lost the link!
×1
3 pin wire connectors
×12

Software apps and online services

Arduino IDE
Arduino IDE

Hand tools and fabrication machines

Hot glue gun (generic)
Hot glue gun (generic)
Soldering iron (generic)
Soldering iron (generic)

Story

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Schematics

Schematic

Code

Defining the FastLED array as a big list of all LEDs chained together

Arduino
CRGB *leds;

void setup() {

  leds = new CRGB[NUM_LEDS_TOTAL];

  uint16_t startIndex = 0;
  FastLED.addLeds<NEOPIXEL, PIN_1>(leds, startIndex, NUM_LEDS_PIN_1);
  startIndex += NUM_LEDS_PIN_1;
  FastLED.addLeds<NEOPIXEL, PIN_2>(leds, startIndex, NUM_LEDS_PIN_2);
  startIndex += NUM_LEDS_PIN_2;
  FastLED.addLeds<NEOPIXEL, PIN_3>(leds, startIndex, NUM_LEDS_PIN_3);
  startIndex += NUM_LEDS_PIN_3;
  FastLED.addLeds<NEOPIXEL, PIN_4>(leds, startIndex, NUM_LEDS_PIN_4);
  startIndex += NUM_LEDS_PIN_4;
  FastLED.addLeds<NEOPIXEL, PIN_5>(leds, startIndex, NUM_LEDS_PIN_5);
  startIndex += NUM_LEDS_PIN_5;
  FastLED.addLeds<NEOPIXEL, PIN_6>(leds, startIndex, NUM_LEDS_PIN_6);
  startIndex += NUM_LEDS_PIN_6;
  FastLED.addLeds<NEOPIXEL, PIN_7>(leds, startIndex, NUM_LEDS_PIN_7);

  // ...
}

Defining a simple data structure for the disc info

Arduino
struct Disc {
  uint8_t discIndex;
  uint8_t numLEDs; // number of LEDs in this disc
  uint16_t offset; // number of LEDs in tree before this disc
  CRGB *leds; // the LEDs for this disc
};

Creating Disc instances, while accumulating an offset to track the disc’s position in the whole tree

Arduino
void setup() {
  // ...

  uint16_t offset = 0;
  for (uint8_t d = 0; d < NUM_DISCS; d++) {
    Disc disc = {d, NUM_LEDS_DISC[d], offset, &leds[offset]};
    discs[d] = disc;
    offset += disc.numLEDs;
  }
}

Set each disc to a different color of the rainbow!

Arduino
void loop() {
  for (uint8_t d = 0; d < NUM_DISCS; d++) {
    for (uint8_t p = 0; p < discs[d].numLEDs; p++) {
      discs[d].leds[p] = rainbow[d];
    }
  }
  FastLED.show();
}

Here's the full code on GitHub

Credits

Michelle

Michelle

2 projects • 2 followers
I like learning about programming LEDs for art installations, and creative coding in general. I also love drawing diagrams and soldering.

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