Very cool. 5-fold symmetry on the PCB to use up the board allowance is particularly neat.
A trick that poor hobbyists learn early on is to make pads a little larger than necessary for SMT parts so you've got somewhere to wick solder onto. Neopixels (5050 LEDs) are reasonable to hand-solder since the pads extend up the sides of the package, but you can also do QFNs with a bit of practice by placing a big via to get to the central pad from underneath.
Love how the 5 PCBs slot into each other to form the final shape.
With respect to the assembly: do yourself a massive favor and let the PCB fab also assemble the LEDs. With a simple bill of materials like this it will add very little cost, it saves you a _lot_ of time, and it might also reduce the chance of component damage from adding too much heat or from accidental ESD strikes. (I don’t know how much these Neopixels can handle, though.)
I'll bet there's some creative board layout so that the relevant controller IC and supporting passives can be soldered onto the back of one of the 5, then have solder jumpers or some such to actually connect it into the circuit. That way, you're not adding miles of unused trace to an active bus.
Of course, having a 5x PCB fab, but 4x+1 assembly would probably double the cost for a single turn of the device.
I would love to hear more about the process of making 5-fold symmetry work for board layout. That sounds maddening to get right.
As long as you can design the outline as a vector file somewhere else, it's easy enough to import as a board outline and then lay out on top of it. I also get the lure of assembly these days, but I would hand-solder a board like this for a one-off art project. Call me old fashioned, but I'm confident enough with soldering that I'd estimate a couple of hours to assemble and I like buying domestic which is less economical than the JLPCB special. If people started to ask for kits though...
I think your idea is pretty sound if you connect all but one of the boards in a ring and use a jumper for the control section.
I could go either way on hand-soldering a single assembly. But doing this more than once would be torturous.
I can only go so many days carefully monitoring diet and minimizing stimulant intake to minimize associated tremors. And I don't have rework microscope, so my eyes would definitely suffer.
I'm still not perfectly happy with the audio response, tbh. But it mostly suffices.
I experimented with both approaches, and landed on mixing the band energy normalized by global energy vs. per-bin max energy, with a very arbitrary coefficient that seems to work. I also keep a few copies of the levels per band with different rates of decay, so I can add features in the sketches which should be sensitive to transients, vs. features which can rely on slower rates of change.
Not at all an expert in any of this and it was a lot of trial and error, still lots of room for improvement.
I understand it was inspired by https://en.wikipedia.org/wiki/Phyllotaxis, but arrangement on leaves serves the purpose of growth in a specific niche. The pattern arises because naturally leaves serve to capture light - see the images on wikipedia there. Phyllo means green. The LEDs used here do not really tap into any of that, and the name is also a misnomer. That's not good.
I disagree with sibling comments. You are correct to express the confounding implications of a word choice. And they have only detracted from the point you make.
Of course the design is cool and beautiful, but it is not the thing it is called here.
The pattern in OP's project is called phyllotaxis. This is supported by the link you provide which gives even looser examples that are still described as "exhibiting phyllotaxis".
I had this concern at first, but using a glue stick seemed fine. The gluing doesn't have to be extensive either, since the paper gets clamped between the plastic parts when I screw it together.
I took the very thin 3D printed cell outline shape, a grey screenshot in my post, and used it to trace the mulberry paper. Then cut and glued paper onto the bottom of that cell outline, and screwed the outline plate into the main assembly.
This is by far one of the biggest areas where I could improve the design. I'm not happy with how fragile it is. The good thing about using just paper screwed from the top is it's thin enough to prevent light bleeding between cells.
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[ 4.3 ms ] story [ 50.0 ms ] threadA trick that poor hobbyists learn early on is to make pads a little larger than necessary for SMT parts so you've got somewhere to wick solder onto. Neopixels (5050 LEDs) are reasonable to hand-solder since the pads extend up the sides of the package, but you can also do QFNs with a bit of practice by placing a big via to get to the central pad from underneath.
Always good to think about if you can get an iron on there during design...not only pad size but component orientation/location.
At times the difference between "easy to rework" and "impossible to rework without removing other components" can be just a 90deg rotation.
Perhaps an example of convergent evolution? :)
https://en.wikipedia.org/wiki/Voronoi_diagram
Where do you see similarities?
https://music.apple.com/us/album/neon-pattern-drum/134973653...
With respect to the assembly: do yourself a massive favor and let the PCB fab also assemble the LEDs. With a simple bill of materials like this it will add very little cost, it saves you a _lot_ of time, and it might also reduce the chance of component damage from adding too much heat or from accidental ESD strikes. (I don’t know how much these Neopixels can handle, though.)
From the article:
What's next? ...using PCB assembly...
Of course, having a 5x PCB fab, but 4x+1 assembly would probably double the cost for a single turn of the device.
I would love to hear more about the process of making 5-fold symmetry work for board layout. That sounds maddening to get right.
I think your idea is pretty sound if you connect all but one of the boards in a ring and use a jumper for the control section.
I can only go so many days carefully monitoring diet and minimizing stimulant intake to minimize associated tremors. And I don't have rework microscope, so my eyes would definitely suffer.
Also works for artwork.
I experimented with both approaches, and landed on mixing the band energy normalized by global energy vs. per-bin max energy, with a very arbitrary coefficient that seems to work. I also keep a few copies of the levels per band with different rates of decay, so I can add features in the sketches which should be sensitive to transients, vs. features which can rely on slower rates of change.
Not at all an expert in any of this and it was a lot of trial and error, still lots of room for improvement.
Thank you for sharing the build process.
I understand it was inspired by https://en.wikipedia.org/wiki/Phyllotaxis, but arrangement on leaves serves the purpose of growth in a specific niche. The pattern arises because naturally leaves serve to capture light - see the images on wikipedia there. Phyllo means green. The LEDs used here do not really tap into any of that, and the name is also a misnomer. That's not good.
Of course the design is cool and beautiful, but it is not the thing it is called here.
Too bad. Software audio visualization's no longer common. But hey your hardware visualization's better than software! :D
This is by far one of the biggest areas where I could improve the design. I'm not happy with how fragile it is. The good thing about using just paper screwed from the top is it's thin enough to prevent light bleeding between cells.