Key components

The light core, which consists of strips of LEDs stuck to 80/20 extruded aluminum beams
The finished walnut housing, which holds the diffusers and shapes the light
The control box, which hides away all the control electronics and is attached to the ceiling
The ceiling mounts, which are just ⅜" plumbing fixtures and a 3D printed part
The main LED controller, hiding in a nearby closet, which has many channels of programmable LED control

All the design for this project has been done in OpenSCAD. This allows the design to be fully parametric and adjustable.

Design goals

Be a great kitchen light
Elegantly blend into the space
Maximum flexibility
Network control
Party hard

For elegance and blending into the environment, this lamp should be as slim as possible and use materials that are already found in this space. The finished walnut housing matches other wooden details already in our kitchen. Having dimmable lamps facing downward as well as upward allows for a ton of flexibility. Party mode should be invisible until it's activated, but when it's active it's on. It should tie into the other programmable LEDs being installed throughout the house.

LED details

I used WS2815 RGB LEDs both in part because the 12V power rails let me run a longer run without power injection, as well as their 2kHz PWM frequency. It's not the best on the market (that would be the SK9822 at 8kHz or APA102 at 19kHz), but at least it's not 450Hz. The DMX white LED driver I got happens to clock in at 8kHz, which was a delightful discovery.

For LED control, I'm using the Falcon F16V3 RGB LED controller. This will be used for a number of other LED art installations I'm working on around my house in addition to the kitchen lamp. This will give me a slick 30-60FPS of LED animation possibility, controllable easily through Python or TouchDesigner.

Housing

I wanted the lamp to have a classic classy look, match our dining room table which sports a dark reddish stain, and be relatively slim. I also specifically wanted the light to form a ring, as from photography I am familiar with the magical power of ring lights.

I measured the kitchen island, subtracted an amount that made logical sense, then mocked up a cardboard version to see what it would look like. With some minor tweaks, I was able to come up with some rough dimensions.

I've learned from working with LED strips for other projects that it's really useful to have your housing match the natural stride of your LED strips. That is, for the 60 LEDs/meter strips that I'm using, having the dimensions of the things the LEDs will be adhered to snap be laid out in 16.667mm (1/60/m) increments. I made sure that the white LEDs and the RGB LEDs had matching strides, though the white LEDs have their cut points in larger groups of 3. This then locked in the final dimensions of the lamp.

I knew I wanted to have the core of the lamp be rigid, possibly heat-dissipating, and easy to work with. I've been working with 80/20 extruded aluminum for another project and decided to order some of that. This made it super easy to adhere the wooden side panels to, gave the LEDs something to put some of their heat into as well as something to stick to. It's also dimensionally-precise and can be easily drilled with hand tools.

LEDs used for lighting a space work best when the...

Complete!
Steve Pomeroy • 07/21/2020 at 03:17 • 0 comments

With the installation of the diffusers, the lamp is now complete.
For diffusion, I opted for Optix LED Satin HDF which has a matte side and a textured side. I thought the textured side adds a nice bit of detail and with 92% light transmission, I wasn't really losing anything. Usually diffusers that offer the kind of scattering this provides ends up with light loss of upwards of 60%, so this was a great find.
The material was only available in 2mm thickness, so I ended up slotting them into the grooves instead of giving them a lip and having them sit flush with the bottom of the wood.
Because I don't really have a full workshop set up yet, I ended up mitering the corners using a 45° rule and scoring+snapping. It worked well enough, but some of the angles didn't come out perfect and I had to hand file them to fix things up.
I didn't miter the diffusers on the top lights to keep things simpler. I don't think there's any loss of quality with the small holes there. The only downside is that this may be a place dust can get into the lamp over time.
Over all, I'm very pleased with this project. I could have done some of the woodworking better, but considering I don't yet have a shop set up and this was my first project, I feel like it's a net success.
Gesture interface
Steve Pomeroy • 07/16/2020 at 03:55 • 0 comments

For fun—probably not for production—I whipped up a quick gesture interface for the kitchen island lamp.

It's triggered when your hand is directly above the Leap Motion controller. Raising/lowering your hand controls brightness, tilting it forward/backwards controls whether the upper or lower lights are lit, and tilting it to the side (rolling) fades between white lights and the RGB ones with a pattern playing.

It feels (and looks) like magic!

If I decide to actually use something like this in production, I may need to switch from absolute positioning to relative positioning. That is, to brighten the lamp, you put your hand in the target area and raise it. That would prevent the lights from flickering when you first put your hand back within the sensing area.
This was made in TouchDesigner using a Leap Motion controller and a ton of Math CHOPs.
Housing installed
Steve Pomeroy • 07/10/2020 at 04:00 • 2 comments

Success! The housing has been installed. Some of the mitered corners will need some tuning so that there isn't light bleed, but they fit generally pretty well!

The main component remaining is a diffuser on both the up and down lights, so that there aren't harsh shadows. I ordered some Optix LED Satin HDF which has a nice texture, excellent diffusion, and 92% light transmission. They'll be cut mostly to size from the reseller, I'll just need to miter the corners.

I'm super excited with how well the lamp looks in both white and RGB mode, even without the diffusers. Check out this fun pattern:
Finishing the walnut housing
Steve Pomeroy • 07/08/2020 at 12:00 • 0 comments

The housing for the lamp is almost finished. All that remains now is putting holes in the sides to attach it to the 80/20 light core.

The housing consists of ⅛" × 3"×48" walnut strips that have been trimmed, mitered, sanded, and finished. To make the long sides, I joined two strips with a simple lap joint and tried to match the grain a little. I chose sides such that the natural curve in the wood faces the aluminum so the entire thing will be pressed flat when screwed down.

On the backs, I cut 3mm grooves 1.5mm deep and 2mm away from the edge with my router table. This will hold the acrylic to diffuse the light on the bottom and protect the LEDs from dust on the top. The acrylic will have a matching lip cut into the edges so that the bottom of the acrylic will be flush with the bottom of the wood to create a very clean look.
The finish is a dark walnut stain with two coats of polyurethane on top. I used wood conditioner because I wanted to see what it did and that brought out the natural color. I almost decided to not stain it, but my partner recommended that I go with the stain to make the wood pieces match better.
Working on TouchDesigner support
Steve Pomeroy • 07/07/2020 at 16:48 • 0 comments

While I'm not entirely sure I'll use it in production, I've been playing with driving the lamp with TouchDesigner.
Finished the electronics
Steve Pomeroy • 06/30/2020 at 21:06 • 0 comments

I finished the electronics today. The RGB and white LEDs on both sides can now be controlled via the main controller over sACN/E1.31! I tested everything out with QLC+.
The DMX controller seems to work just fine without a ground wire. My understanding of this is that RS485 and thus DMX requires a common mode voltage between -7VDC and +12VDC, so as long as the grounds between my two power supplies (one for the main controller, the other for the lamp) don't have a voltage differential greater than that, then I'm fine. They're on the same house AC and are made by the same manufacturer, so that probably helps.
Light core installed on the ceiling
Steve Pomeroy • 06/30/2020 at 13:09 • 0 comments

I test-fit the core lighting system on the ceiling and tried out the white LEDs (up and down at the same time). Interestingly, the upwards white LEDs create a very rectilinear shadow of the wires on the ceiling. The effect is not bad, but also not intended. I'm going to roll with it, though: the room illumination it provides is excellent.

The RGB LEDs work great too:
Of course, this is only showing off the fact that all the LEDs light properly and checking out the light levels. Every one of the LEDs can be controlled, there's a ton more possibility than just a single color at a time. The downward RGB LEDs will be diffused and the upward ones will just have a clear dust cover on them, so the final effect will be very interesting.