I’m looking to make a desk feature which has mini colour changing rbg led strips tracing the edges of 20 connecting 2 inch triangles into a 3D icosahedron.
The idea is to use two way acrylic triangle mirrors, a 3D printed frame, and the interior edges lined with LED strips. It’s been done before but I’d love to make a mini one that sits on a desk. Bonus points for battery power.
I’m here to talk about the electronics side of things. I’d need 1.5m of LED strip lighting and I’d imagine it would have to be quite thin.
I’m not very well versed in electronics and haven’t soldered before, but I’m willing to try it out.
Do you have any suggested products that would work with something like this? (I saw the neopixel 1515 LED strip and liked that you have individual LED control and a thin strip).
I’d imagine that I would need to cut the strip into 30x 2 inch sections as well so that’s a lot of soldering. - I also have no idea how to control or power the lights.
If you also have any other suggested parts including connectors and small footprint control boards (Pre-programmed? Easily programmable? Smart phone compatible?) that would be awesome! I’d love to be able to loop through different effects and colours, from tracing to fading, to randomised twinkling.
And finally as budget friendly as possible would be great!
- 20x Equilateral triangle faces
- 30x 2 Inch Edges
- 12x Corners
Hi, that sounds pretty interesting, how many LEDs per edge were you thinking? It be worth basing it on that, rather than a fixed size. For example, you could use a GlowBit™ Stick - 1x8 | Core Electronics Australia but it’s 54.8mm long, and you’d need 20.
If you just wanted them on each vertex, it’s a bit easier as you can have a single path chaining them all together. For edges it’s harder, there’s no single path that visits every edge only once, but (I think) you can do about 25 edges in a single run, then (I think) the rest are disjoint. (see this on math stack exchange
In any case: you probably don’t want to cut each individual edge from a strip, it’d be way easier (less soldering) to work out the longest sections you can. Also to base the size of the shape on the spacing of the LEDs on the strips. e.g. LED RGB Strip - Addressable, 1m (APA102) | Sparkfun COM-14015 | Core Electronics Australia are 16.6mm apart
The way the addressable LEDs work is each has 4 connectors: +ve (usually 5v), ground, Data in, and Data out, then you daisy chain them all together. You only really need to chain the Data in to data out, and you have +ve and GND common for all the sections.
For the programming you can have a look at the glow bit libraries, you’d have the the LEDs in one big array can address them from there, you could drive them all from a raspberry pi pico w and you’d be able to control it from your phone via wifi. The power would be a whole different issue and you might struggle to power them all off a battery
It sounds like you’ve got most of the parts down, as for this aspect, I’d check out WLED. Tim has an excellent guide and video here:
Take a look and let us know if you have followup questions
Awesome! Honestly those sticks look like a great option. I think I can get the acrylic cut to match that dimension.
As far as the daisy chaining goes I’d need to connect thirty of those sticks. Do you know if I need to do anything special with the power supplied to it? Like what sort of power and data supply limitations there are?
I was thinking of making a 3D printed exterior frame for it to hold all the LED’s so perhaps that could also house additional wires that could sneak behind the sticks inside the frame if ever I needed to go past an edge more than once.
The edges would have a much cooler look I’d say!
Thanks so much for your reply that’s awesome!
Brilliant! Y’all are the best.
I just saw this vid, makes perfect sense!
So if I were to chain 30 GlowBit sticks together I could use this and one ESP to control them all?
Looking at this 5M RGB LED Strip - WS2812B 30 Per Meter - White Strip - Weatherproof | Core Electronics Australia is says 1.1A/m or 5.5A for the full 5m. That works out to about 36.67 ma per LED, so you’re going to have 8x30 = 240 LEDs * 36.67 mA = 8.8A, so I’d get a 10A 5V power supply, that sounds like a lot, so my maths may be out. However: a single controller can easily drive all the pixels.
Another option is to use a software power limiter. If you know the power supply is only capable of 2amps, apply a brightness adjustment to the LED data before passing it into the WS2812 library of choice.