Table of Contents

The Result

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Media ID: B4vFUBwor-C

This project is still work in progress. The necessary files are listed below in case this is all you need.

The Parts

Amount Part Type Datasheet Links
1  STL file + blender sources STL   💾
2x  LED Lightstrip ~55 LEDs 144led/m (about 40cm) LED   🔎 aliexpress

The 144LED/m lightstrips I got are divided into 72LED segments with a gap where they are linked, so if you get 1m of 144leds/m, you will have to cut it in half, and then trim both halves to about 55 LEDs.

The Schematcis / The PCB

//TODO My initial idea was to create a custom PCB for this lamp, and left some space in the base of the model.

The lightstrip needs 5V logic. If you use an ESP8266 or equivalent controller with 3,3V logic, you will need a level shifter. In the end I designed a general purpose two channel ws2812b driver, that will get its own project page.

I might redesign the base a bit for the generic driver.

The 3D Print

As you can see in this image, I designed the WS2812B LED strip in Blender and modeled the DNA Strand around it.
This is the first part. The top prints without supports, but you should test if you can bridge a distance of 8-9cm first.

It took me around 8-9h to print at 0.3mm, 60mm/s.
Click on the image for a bigger view.
The button part is very generic, so you have enough room (2cm height) to add your electronics or batteries.
The hole (for example for a USB cable) has a radius of 1cm.

Click on the image for a bigger view.
I printed the top with white PLA, the bottom with a black PLA.

Assembly notes

The green cable is DIN, passing the signal to the next LED (higher index)

Be careful not to destroy the lightstrip when inserting it into the lamp. If you do have a break in the lightstrip: I let mine run at 100% brightness and let it heat up over an hour it magically fixed it self. Or I was lucky and should never move the lamp again. Also, do not remove the cover of the sticky tape, it will get stuck half way in.

The “ladders” of the DNA helix are spaced such that every 6th LED hits a horizontal bar (which are hollow). As you can see in the preview video above, I added an animation while inserting it so I could align the LEDs correctly. Then I hot glued the lightstrip in place.

Make sure to shake it slightly to see how the lightstrip falls into place before hotglueing.

You can see where you insert the light strips from the bottom, and how I hotglued them.
This is a preliminary solution for now ;).

The Code

See my github repository: pauls-3d-things/esp8285-ws2812-contrller:devices/dna-light