Motivation

Building a smart animated decorative light.

The idea was to stuff an empty magnum Campari bottle with randomly placed RGB LEDs that can be set to a Campari red color. Each LED on the strip (WS2812b) can be controlled individually with an arduino-like microcontroller (I used ESP8266 which is smaller and has wifi). Watch the video to see the final result.

2D Mapping (3D soon)

Since the LEDs are indexed from 0 to n-1 as they appear on the strip, I needed to map them to where they actually are located in space. I wrote a simple C code to light them on one at a time every 200 milliseconds:

uint32_t colorOn=strip.Color(70, 70, 70); // Any RGB color
uint32_t colorOff=strip.Color(0, 0, 0);
  for (int i=0; i<LED_COUNT; i++) {
      strip.setPixelColor(i, colorOn);
      strip.setPixelColor(i-1, colorOff);
      strip.show();
      delay(200); // Wait 0.2 seconds between pixels
    }

I took a video in a dim room and processed in python (see the notebook):

Animation

I loaded the coordinates into a C array, and made a simple animation that includes a drip of Campari filling up the bottle and an animated sine wave function at the liquid-air interface.

OTA

The C code includes default OTA blocks that allow pushing code updates over wifi (ESP8266 and other wifi enabled microcontrollers). These blocks are optional and if you are using an Arduino they should be removed.