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Tinkering Tuesday – Playmobil Stage – LED Rings

Past posts of this series:

Tinkering Tuesday – Playmobil Stage – Einführung

Tinkering Tuesday – Playmobil Stage – Introduction

Tinkering Tuesday – Playmobil Stage – Playmobil parts

Tinkering Tuesday – Playmobil Stage – LED Stage Lights

Tinkering Tuesday – Playmobil Stage – Disco Ball with stepper motor


This one will be a rather short post to describe the LED rings that I used for the background effect.

They are very cheap WS2812B based LED rings from ebay. I bought 3 different ones, 7 LEDs (1,10 EUR), 16 LEDs (2,29 EUR) and 24 LEDs (3,69 EUR). The wiring is very easy, the WS2812B is addressable and requires only 5V, GND and one control pin from the Arduino. They are even chainable so I connected the control pins of all three rings to only require one singel Arduino pin.

In the following picture you can see the wiring. Yellow is the control pin chained from the biggest to the smallest ring. The black ground wire is also chained. I decided to provide the 5V to every ring on its own to avoid a loss of brightness (but I guess with only 47 LEDs that was not really necessary). I even made a professional looking schematic, see the small orange paper in the pic?!

Soldered and chained rings

In the next picture you see the solder pads in a closeup.. Here is the smallest ring only connecting the input side (black=GND, red=5V, yellow=control pin). As you saw above I secured everything with hot glue.

Solder pad closeup

Here it is already glued to the back of the stage:

Glued to the background

As a beginning I searched for an easy to use library and found FastLED. They are also compatible with Adafruits NeoPixel. So go have a look there. They have great guides.

The most simple program using it is:

#include "FastLED.h"
CRGB leds[1];
void setup() { FastLED.addLeds<NEOPIXEL, 6>(leds, 1); }
void loop() {
leds[0] = CRGB::White; FastLED.show(); delay(30);
leds[0] = CRGB::Black; FastLED.show(); delay(30);
}

This only blinks the first LED. There are some more great examples in the download from Github and the basics are very easy.

Here is a small test video switching all LEDs one after another from red to yellow to blue:

I wanted to use something with a little more effects than just blinking like with the LED spots so I chose one of the bigger examples, the NoisePlusPallette which can be found at: https://github.com/FastLED/FastLED/blob/master/examples/NoisePlusPalette/NoisePlusPalette.ino

This is using readymade color palettes and combines that with a random noise generator. You can influence the parameters (e.g. with the sound input) and so make this you own. I didn’t have so much time so I just fed in some parameters from my sound input and adapted it to the number of LEDs. The result will later be described in my Software wrapup.

I used acrylic glass that I sanded so it is not clear but milky to make the effect more outstanding. That will be seen later in the woodworking part. In my demonstration video you can see the rings in action (here directly starting at 0:11):