Optical Fibers and LEDs - Three Projects

In this article I want to share with you three projects I made with the help of optical fibers and WS2812 LEDs. I know that I have already presented two other projects "Fiber Optic and LEDs - a Wall Decoration" and "Fiber Optic LED Lamp" so... I will put on hold the rest of the ideas that I might present in the future.

This time too, I wanted everything to be as simple, flexible and easy to implement as possible for everyone, but it is necessary to either have a 3D printer or use a 3D printing service.

The basis of these three projects is a 3-piece modules as in the photo below.

You can see that the important part of this module is a ring in which a piece of tape with 6 LEDs can be mounted, and it has 12 holes in which the 3mm diameter PMMA optical fiber can be inserted. The module also contains a support and a cover that I will use for several purposes in the projects below.

All STL files for the base module but also for other printed parts used in the following three project are on Tinkercad.

Let's get to work !

The first project is very simple and is an interesting decor that can be used for example in children's bedrooms, or in nursery rooms, kindergartens, choosing some soothing pastel colors that can create a calm and restful atmosphere.

We need :

• PMMA optical fiber of 3mm - approx. 3m;
• Basic module, 3 or even more pieces - printed with colored PLA (yellow, orange...);
• A few pieces for the leaves and the appropriate lids 3 - 5 pieces - printed with green PLA;
• Small case for Arduino Nano 1 pc;
• LED strip (60leds/m) part with 6 LEDs each 3 pcs;
• Arduino Nano (or Pro Mini or Uno) 1 pc;
• 5v/1A power supply with mini USB output;
• 6mm green heat shrink tubing or (other green colored plastic tube) 2 - 3 m;
• Connection wires.

Construction

We start by printing the basic modules. If we want to have leaves, then we also print the corresponding pieces and covers. We glue the power and data wires to the LED strip pieces and mount them in the rings and in the leaf pieces. We insert pieces of optical fiber of equal (or unequal) lengths in the ring as in the pictures above. Using a screw, fix the base to the wall and mount the ring with LEDs on them. We also fix the parts for the leaves. Pass the connecting wires through the green heat-shrinkable tube and make the connections. The data input from one strip is connected to the one digital output of the Arduino module as you can see in the code below. The power supply with the mini USB plug is inserted directly in the Arduino module. We load the software and start the installation.

Software

It's a short code adapted from the FastLED library example, I uploaded it below. In essence, the LEDs on the petals light up in palettes of red, blue, orange, purple, pink and the leaves in different shades of green, green-yellow, green-blue that change at intervals of 20 seconds.

How is it working...

You can watch the work of the set in the video at the end of the article. I mounted everything, for demonstration purposes, on a drywall board. You can use several outputs of the Arduino Nano, each connected to a different flower stem or you can use one output for several stems even combined for several flowers. Of course you can only build the flowers without stems, without leaves and hide the wires behind the panel ..

For this project in addition to the basic modules, some connecting parts must be printed. With the help of these parts you can connect two basic modules and with the optical fibers the two modules can be joined as in the photos above.

We need:

• PMMA optical fiber of 3mm about 6m but depends on the size and number of "globes" we make;
• Base module, for each globe 2 rings, 3 backs and covers;
• Three connecting pieces;
• Hooks
• Small case for Arduino Nano;
• Pieces of LED strip (60 leds/m) with 6 LEDs each 6 pc;
• Arduino Nano (or Pro Mini or Uno) 1 pc;
• 5v/2A power supply with 5.5/2.1mm DC male socket 1 pc
• Cable with a 5.5/2.1mm DC mother plug 1 pc;
• Screws, nuts, washers M3;
• Connecting wires, heat-shrinkable tube.

Construction

In the beginning, of course, we print the necessary modules and parts. We prepare the pieces of LED strip with 6 LEDs and mount them in rings. For the rings at the bottom of the "globe" it is not necessary to solder the wire to the data output. We mount the LEDs in the rings and assemble everything as in the photos above. When mounting we can shift the upper ring with a position compared to the lower one, but it is important when mounting the optical fibers in the holes of the rings to be sure that the fibers have a LED at one extremity. We also make the connections to the Arduino Nano module (consult the code for details), load the software and start the installation.

Software

The software is exactly the one you can find on github, I also used it in my previous project “Fiber Optic Wall decoration”. In short, different color palettes are displayed with a subtle transition from one color palette to another. You can also see the necessary changes in the code attached below.

How is it working...

In the same video at the end of the article, you can see the operation of the globes, from 0:45. Of course you can add more color palettes to play with them, you can find many other examples of color palettes on the cpt-city website.

Using several rings of the basic module, covers and supports we can build a very similar installation to a lantern. It is not a heavy construction at all, although it seems so at first sight. In addition to the parts mentioned, some connecting-rings must be printed, as you will see in the list below

We need:

• PMMA optical fiber of 3mm about 7m (but depends on the size, number and fibre models of the "lanterns" we make);
• Base module, 14 rings (8 and 6 pieces respectively), 3 bases and three covers for the two lanterns;
• Connecting-ring 12 pcs;
• Hooks 2 pcs;
• Case for Arduino Nano;
• Pieces of LED strip (60 leds/m) with 6 LEDs each 14 pcs;
• Arduino Nano (or Pro Mini or Uno) 1 pc;
• 12x12x7mm switch button 1 pc;
• 5v/2A power supply with 5.5/2.1mm DC male socket 1 pc;
• Cable with a 5.5/2.1mm DC mother plug 1 piece;
• Screws, nuts, washers M3;
• Connecting wires, heat-shrinkable tube

Construction

We print the required parts to the 3D printer. Cut the pieces of led strip and glue the connecting wires. I chose that the LEDs in the two lanterns be in series, ie the output wire given from the first lamp to be connected to the next. Mount the strip pieces in the rings. We start the hardest part :) Insert, as straight as possible, the first connecting ring in the first ring of LEDs at the base so that the spikes from the connecting ring are visible (approximately 6mm). We must be careful to align the spikes of the connecting ring with the holes of the LED ring. Fix this position with a few drops of hot glue. We insert over the connecting ring the second ring with LEDs so that the holes are aligned and those in which there are LEDs are one below the other. However, I rotated the second ring 180 degrees so that the connecting wires did not clog on one side of the inside of the flashlight. I then made the connection between the data output of the upper ring and the data input of the lower ring. If the LED ring rotates on the connecting ring you can put a few drops of hot glue to block the movement. I continued like this until the last ring. 8 wires (red) +5v and 8 wires ground (black) and two wires were connected: input data (blue) from the upper ring and output data (green) from the most lower ring. I gathered the power wires together and so they had only four wires in the end. I then mounted the hooks on the lids and inserted the covers into the top of the lantern. The most interesting part was the installation of optical fibers. There are many possibilities, I chose two models for the two lanterns; you can see in the photos and in the drawing below how I made them.

The connections are then made to the Arduino module (as stated in code D5 for LED output and D2 for the button input), for the button, between the two lanterns and between the Arduino Nano and the first "8-stage" lantern. You can follow all these operations in detail in the photos above, I hope they are conclusive.

Software

The program I used for these lanterns is the one I used for my previous project "Led Lamp" only the number of LEDs had to be changed:

#NUM_LEDS = 84 

As in the project mentioned above, with the help of the switch button you can change the way the lanterns work.

How is it working ...

In the next step you will be able to watch in the video, starting at 2:40, how the lanterns look during operation.

Here you can see how the three projects work, I hope it is edifying...

It was very interesting to experiment with these modules although I had some problems.

At first I tried to use colored PLA for the flower project and white PLA for the rest of the projects but in the tests I noticed a very annoying LED light bleeding. At the flowers I tried to decrease this bleeding by printing the caps with 100% fill, with little success but for the rest I had to use darker PLA, so I chose an aluminum gray PLA that gave good results.

Also, in the process of the construction, I noticed some things that I missed during the design but I managed to solve them. All in all, I think you can do interesting things with these modules.

I hope you like my projects and I look forward to your feedback, as always :D