Tag Archives: led

LED Lighting Primer – Part 4 (Native LEDs)

Forget the Bulb

I have replaced most of the traditional lights in our house now, with a plan to purge the rest over the next couple of months. However, for new lighting in the house, I’m starting to look into LED native solutions. A good example of this is the task lighting I added to the kitchen.

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This kit provides you with 10 8″ 2700K LED bars, wiring connections for them, 2 transformers, 2 small switches. The install is very quick, and you only need a spare outlet somewhere.

Susan had been asking for counter task lighting for years, and I was basically stalling until we had an LED solution for it, which wasn’t really there 2 years ago (the last time I looked seriously). We’ve now arrived.

For our kitchen I only used half the components in the kit. The bars are bright enough that a single row is the right brightness. There are 4 under the main cabinet, and 1 that’s under a side shelf in the corner. I’m still contemplating where the rest of the kit is going to be used.

RGB Lighting

Susan and I took a flight to India for a wedding in 2008. We flew on a new 767 that had a color changing LED light kit that meant that we got simulated sunrise (deep red -> orange -> yellow) and sunset (orange -> red -> deep purple) during our flight near meals. This was amazing. My entire interest in LED lighting started with this experience, as I wanted that in my home. I have parts and experiments scattered across my electronics workbench that never quite got far enough to be useful. Now you can buy this off the shelf.

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Living room with Hue RGB light strip and Iris color pot

There are a few different systems out there. I bought into the Philips Hue universe for a couple of reasons. The Hue system includes a “bridge” which connects to your home network (wired only). It then communicates to up to 50 Hue devices via zigbee, which is a low powered wireless protocol that lives in the 2.4 Ghz spectrum.

They have a very open API, which means there are tons of 3rd party applications that can talk to Hue. That includes applications that do things the base system does not, like color animation (aka simulated sunset). Plus you can write your own.

They make regular A19 bulbs, unique color pods for indirect lighting, and connected light strips. They are definitely in a different price category than regular lighting, but if this is your thing, they are pretty awesome. And this was definitely awesome enough for me to spend some time and money to experiment with.

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They make a scene switch for these lights which you program via smartphone app. It’s actually 4 buttons, as the whole thing clicks in. Typically 1 will be off, then 3 different configurations. For our bedroom I’ve put Hue bulbs in both of our night stand lights. 2 is roughly a 2700K full brightness. 3 lights up only Susan’s light on the lowest reddest bulb setting. This is to give her just enough light for nighttime feedings for Arwen, with hopefully the ability to get back to sleep after. 4 is currently a mellow orange light, just because.

Button 2 - Normal Light
Basic soft white light
Button 3 - Red Feeding Light
Note the hallway light difference from the prior, this is actually extremely dim, and the camera is compensating with much higher iso.

What’s super cool is once you have a few of these you start thinking about the lighting in your house in a different way. We can set the lights to a very low level while watching TV, so you can still see in the room, but it doesn’t impact the watching experience. I’m leaving the living room ones on at the lowest red level.

Note – not quite RGB after all: 

One last thing I discovered on Hue is that the A19 Bulbs actually live in a different color space than the “Friends of Hue” gear like the Iris or Light Strips. The bulbs are optimized for nicer whites so they can act like normal bulbs. Which means they can’t do a super deep red, and don’t do cyan at all. The Friends of Hue are optimized for color control, which means their whites are a little odd, but their deep colors are really straight on. So depending on whether you’ll be using this more as normal lights, or more in color accents, choose accordingly.

The Future of Lighting

I’ve been listening to BBC’s History of the World in 100 objects, which has made me think a bunch about long term evolution of objects.

The history of light is a curious thing. It’s kind of amazing to think that the way we got light in the 20th century is to run so much current through a wire that it heats to the point that it glows white. Then put it in an evacuated glass sphere to prevent it from igniting. Fluorescent lights use a bit more physics, but are equally baroque.

But LEDs are extremely malleable. They come in all kinds of shapes and sizes. Honestly, it wouldn’t surprise me if the ceiling fixture standard we know today becomes a thing of the past. To my daughter the light bulb will probably be the same way I think if vinyl records, a thing that I saw as a kid, felt nostalgic about, and now have no place for in my life.

My journey experimenting in this space has just begun. I’ll continue to write about some of this in the future. But hopefully this primer has been useful in providing a base line to let others explore the space as well.

Read the whole series:

LED Lighting Primer – Part 3 (Tube Lights)

Beyond normal screw bulbs in our house, we’ve got a bunch of florescent tube lights. The primary lighting for the family room, workroom, and garage are tube lights, and are old enough that their flicker and hum is something I want to get rid of.

Unlike with screw bulbs, we’re now in a part of the lighting catalog where the major manufacturers haven’t showed up yet. So there are a bunch of options coming from people you’ve never heard of before. It means you won’t find them in any retail stores. As such I’ve been trying a few things to figure out what’s gong to work for me in the long run.

LED Tubes

You can actually get T8 LED tubes which fit in a tube light fixture. You can even get it at 3000K, so you can get a much nicer color than tube lights typically produce.

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LED tube lights

The results are quite good. These are at least as bright as what I was replacing, the color is better. The only interesting thing is that these are on the same switch as a couple of SlimStyle bulbs, and the tube lights are delayed in flipping on by about half a second. I’m assuming lag in the transformer / rectifier.

Installation is a bit interesting, as the LED lights actually have the transformer built in, only have pins live on one end, and just take raw 120V AC across those 2 pins. That means that for a florescent light fixture you are going to gut and rewire it to bypass the ballast, and cut off anything flowing to the far end. This is a one way conversion of that light fixture. All in all it took me about an hour to figure out what I was doing and solder the internal connections appropriately.

But this whole process made me think, once I was all done, I was basically just using the tube light hardware as a holder. Tube light fixtures aren’t exceptionally attractive, so while this is fine the one place I did it, I’m not sure I’d do it again.

Tube Light Tasks

In our home the tube lights are used in 3 rooms: workroom, family room, and garage. I installed the ones in the garage to make it a place I could work on projects after dark. We have a bunch in the workroom for starting plants in the spring. These are used largely because they are cheap, throw a lot of light, and were about all that was available at the time.

LEDs have way less design constraints. You are are starting to get some really interesting designs coming out of Chinese manufactures, now that selling directly to international consumers is a thing. One of my favorites are these 1/2 inch thick illuminated panels that give off 900 lumens with 12W. From what I can tell they are a minimalist package built around a high end CREE (yes the same CREE) super bright LED component. They come in a few different shapes, sizes, and light colors.

Mudder LED Ceiling Panel

Which looks kind of like this in action (taking pictures of lights is hard).

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For overhead bulk lighting in places like the garage, this is probably going to become my go to device. You do need to build a bit of a box for the unit to hang in, but it will still have a lower profile than the tube lights. They’ll also be instant on and not flicker.

Grow Lights

The other place lots of people (including us) use fluorescent lights is to grow plants. We have a small side garden mostly for early greens, peppers and tomatoes. Susan starts everything inside in March and we transplant to the great outdoors mid May.

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We have a lot of science around photosynthesis now, specifically what wavelengths of light are used for these chemical processes. We’ve had that information for a long time, but we couldn’t do much about it until recently, because our ability to create custom colors was limited. You now can actually buy LEDs that nicely land inside those absorption peaks. I was planning on building my own light pods from scratch a couple years ago (I even have most of the parts) but never got around to it. Now you can buy it off the shelf.

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I got one of these to experiment with, it’s currently just pointed at some African violets until we need it for seed starting. Definitely a little trippy. What looks like imaging artifacts… aren’t. The red and blue shadows are really there in real life.

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We’ll probably need 4 total for the grow area we have. We’ll also need to put heating pads under the plants as these don’t generate any heat (the fluorescent lights did) and soil temperature is important to germination.

So the net of all of this is that I’ll probably end up replacing the rest of the tube lights that I have with LED panels (or some other more interesting LED fixture), and use proper LED grow lights for that task.

Design Constraints

By the time I had gotten to tackling the tube lights in the house I was beyond what I could buy at retail, so have been experimenting with some one off purchasing on Amazon.

But modifying that tube light unit really made me think about how many physical constraints have shaped our thoughts about lighting for the past century. The light bulb is a curious set of physics that is about running too much current through a tungsten wire that lives in an evacuated glass sphere so that it doesn’t burn out. Which also explains most lighting fixtures, as they have to be built to protect these lights, and vent the enormous amount of heat they generate.

A very similar set of constraints apply to fluorescent bulbs, with slightly different physics. The CFL was a very odd set of tricks to do what you needed to with fluorescent bulbs in the design point for the Edison light.

LEDs are going to change a lot of the way we think about lighting. If the Edison bulb was stone, and fluorescents are wood, LEDs are clay. A building material that can be reworked into all kinds of shapes and sizes natively. But I’ll dive into this all more in the next section.

LED Lighting Primer – Part 2 (Screw Fixtures)

Note: background on lighting and motivation for this is in Part 1. If A19 or 800 Lumens means nothing to you, I suggest you read that first. Also, all links to products go to my Amazon affiliate referral code. So if you buy anything through this page I’ll get a small kick back. If you find this useful please feel free to do that.

In only the last 12 months things have dramatically accelerated in the consumer LED space, so for a bunch of lighting situations LED replacements is a firmly solved problem. I did a ton of reading on Amazon about various options, but did my first round of purchasing at Home Depot so that I could return items easily if they didn’t work out. I also bought a variety of different kinds of bulbs from different vendors, so I could figure out favorites for future purchases.

Current Major Players

The top 2 vendors in LED replacement bulbs for incandescent or CFL appear to be Philips (who’s been in lighting for ever) and CREE (an LED component company that grew up into this market). Philips and CREE hold the largest shelf space at Home Depot, and my understanding is that CREE has some sort of exclusive with Home Depot, which is probably part of it. While powering LEDs is simple, LEDs are directional by nature, so a huge part of the design is actually efficiently diffusing the light into 360 degress.

Philips was in this game before anyone else, and has produced many different iterations of LED replacement bulbs. They were the winner of the L Prize for a 60W replacement. The precursor to that winning bulb was available for retail sale, and ran about $35 / bulb (when not on sale). I have a few of those because the CFL slow start was driving me nuts in our hallway and kitchen.


Philips LED bulbs” by Geoffrey.landis – https://en.wikipedia.org/wiki/File:Philips_LED_bulbs.jpg. Licensed under CC BY 3.0 via Wikimedia Commons. The bulb on the left was the first widely available commercial LED 60W replacement. The one on the right was the winner of the L Prize for 60W replacement.

It is clear from the bulbs Philips is continuing to produce that they’ve got a heck of a design team that’s into trying new things (which is paying off).

CREE was a new comer to this market, and entered from below, previously just being a parts maker. It seems that CREE has basically figured out one physical design, and is sticking with that. They are putting their innovation into driving cost down, and energy consumption. A Philips 800 Lumen bulb (60W equiv) will be ~10W, a CREE at the same luminosity will run at ~9W.

CREE entering the market definitely put price pressure on Philips and helped open up this whole market. Competition here has been really good for consumers and means that you can now get an 800 Lumen dimmable bulb for less than $10. I got some for $7 at Home Depot. While still more expensive than incandescent, remember, we’re talking about 20 year life on these things, so the amortized cost is actually pretty low.

The A19 (aka Regular Bulbs) story

The A19 space is a completely solved problem. You have a ton of options, they’ll all work quite well. I have 3 models of Philips in the house, and a bunch of CREE. They all act and look quite similarly.

My Favorite LED Bulb (non dimming environments)

philips_slim_line_led

If you were to only get one bulb, and start replacing 60W lights through the house get the Philips SlimStyle 800 Lumen 2700K bulb. This is Philips newest design, in which they figured out how to get 360 degree light diffusion without frosted glass. Which means this is 100% plastic, so dropping it, probably not an issue. It’s also one of the most inexpensive bulbs on the market. Amazon pricing is currently ~$8, I got them for $7 at Home Depot on some sale they were running.

When lit up and complete bare they look like this:

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However the light spread is unidirectional. So either as bare bulb, or in a fixture, these will act as you expect. They are dimmable, but they aren’t the best dimmable performance out there.

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SlimStyle in a paper lantern, notice you don’t see the donut.

The reasons to not get this bulb is if you need something brighter (the 800 Lumen bulb is the brightest they make in this design) or if you are going to dim them.

Pick for Dimming Lights

If putting bulbs in a dimmer, my current favorite is the Philips 429258.

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This is actually an 880 Lumen bulb, so a little brighter. This got the best reviews for dimmable bulbs in a bunch of places, and I’m pretty happy with the results.

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LED bulbs don’t dim all the way down like incandescents do, I think because at the lowest level they are driving so little current it’s not enough to activate anything. So realize you’ll only get down to 15% luminosity, then it goes off.

I did find this bulbs slightly more blue than I expected for 2700K, but our other lights are also all going through shades which yellow it even more. I think if we want to warm up that room the answer is really change the paint on the walls.

Also note, unlike the SlimStyle, this is frosted glass on the outside to get the diffusion. So if you drop it, it could break. It feels pretty rugged so I’m sure it will take more abuse than a CFL or incandescent.

Pick for 3 way Bulbs

When I started barreling down this path Susan mentioned she’d actually like 3 way bulbs in the 3 lamps in the house that support it. As a kid growing up I think I only ever saw a three way bulb once, so it wasn’t even on my radar.

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Both Philips and CREE make them, however the CREE’s click 1 is dimmer (340 Lumens vs. 470 Lumens on the Philips). So CREE 3 Way LED is my pick here. The three we installed work great, and it means we have a ton more control over lighting in the living room.

Like the Philips 429258, this is glass on the outside, so this could crack if dropped.

Higher Lumen Bulbs

I have a few places where I want higher lumen bulbs. I mostly filled this with CREE largely because they were a little cheaper than Philips, and the 100W equiv bulbs were out when I was at Home Depot. So far they’ve been fine.

One of the nice things of the 75W equiv bulb is that it’s still an A19 that uses 13.5W. Which means if you have a fixture that said max bulb was 60W, you can use one of these in it to make it brighter than it’s ever been.

The 100W equiv is actually an A21 shape, so a 1/4 inch bigger around. All the 100W equivs (Philips and CREE) state they are not suitable for enclosed fixtures, though given their power distribution I’m not entirely sure why.

Specialty Bulbs

Beyond the E26/A19 lights in the house, I also have some track lights (not on dimmers) which take R20, and our range hood which takes PAR20. Honestly, I always confuse these 2, so realize PAR20 is the shorter one.

The R20 bulbs are also pretty much a solved problem. Philips has plenty of bulbs in this realm. I think I got some Feit brand for a couple of these, but doing it again I’d get these – Philips 423400.

The PAR20 bulbs are still kind of a work in progress. I got the Philips bulb that was on the shelf at Home Depot, but it turns out it was actually a 3000K 25 Degree beam bulb. So the results weren’t quite what I hoped.

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On further research I should have bought the Philips  426155 which is 2700K and a 36 degree beam spread. Amazon primed. Will have them Tuesday.

But that was the only big mistake I feel that I made during my purchasing, so I’m ok with that.

Refrigerator Door Light

We have a GE refrigerator that takes an A15/E26 bulb in both the fridge and the freezer. It turns out this was actually a 60W incandescent. As I ranted a few days ago, this mean the top shelf of my refrigerator was basically an easy bake oven. This is not what you want.

Neither Philips or CREE are in this space. So I ended up with an off brand bulb A15 40W equiv bulb that was on the shelf at Home Depot. I’m ordering this Feit Electric A15 bulb to do the same replacement for the freezer.

Replacing the refrigerator door light with an LED is probably the biggest win I’m going to get out of this. The refrigerator is running noticeably less often now, and the top shelf is cool to the touch even if you loiter with the door open for a while.

If you do nothing else, figure out how to replace your refrigerator bulb with an LED as soon as you can. Your life will get noticeably better after doing it.

Caveats

In general, I’m not going to buy more Feit bulbs unless I have to. Not because their bulbs are bad, but their packaging is completely out of control.

All the Philips and CREE packaging is recyclable (cardboard + PET (#1) plastic). Feit is not. And their R20 packaging is the terrible extra tamper proof kind that you have to cut apart with a box cutter, create a ragged edge of plastic, which you then cut yourself on. Basically everything that Amazon’s frustration free packaging was designed to fight. And it’s made of a non recyclable plastic. Boo Feit.

The other caveat is that the rule that bulbs don’t hum ends up being violated when they are in a dimmer. It’s arguably still less than CFLs do in a standard light socket, but if you have sensitive ears (and haven’t lost your high end range) you can hear if it you try.

Next Up

I think I have 2 more parts in me, though they’ll come a bit later. One on what to do with florescent tube lights, and one on LED native lighting and the future of home lighting.

As always, if you have corrections or comments, please leave them in the blog. Once all these posts are done I’ll string them together a bit better, and will definitely update with any corrections.

The whole series:

 

LED Lighting Primer – Part 1 (Background)

Apparently the way my fathering nesting instinct kicks in is through home improvements, as I’ve had a brand new motivation to plow through a ton of things while at home for paternity leave. One of the large projects has been the conversion of the whole house to LED lighting.

I’ve learned a lot more about lighting in the process than I would have imagined, and writing it might be interesting to others.  Consider this a primer for the state of the world circa October 2014. And caveat reader, I am in no way an expert, but consider my self an enthusiastic amateur.

Note: I’m going to do this as a multi part blog post, because this is going to be long. Hopefully you’ll find the section you are interested in and pick out what’s useful to you.

Light Bulb Shapes and Sizes

Before diving in it’s worth talking about light bulb shapes and sizes, because, honestly, this confused me for a long time.

The code number of a bulb consists of a letter or letters followed by a number. The letter indicates the shape of the bulb and the number relates to the diameter of the bulb in eighths of an inch. The mosts commonly used household bulb is the A-19. The bulb is “A” type and the diameter would be 23/8″. A 65BR40 is a 65 watt reflector 5″ in diameter.

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– http://www.lightopedia.com/bulb-shapes-sizes

In addition to the shapes of bulbs, there is a whole orthogonal matrix  which is the base sizes.

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Again these are coded with a shape and a diameter. However the diameter for bases is measured in millimeters. So you need metric and imperial units, on the same bulb, to categorize it. I’m sure there is a story behind it, and I’m sure it’s crazy.

While that looks overwhelming the reality is for house hold use you are looking at only a few of these.

Base Sizes you probably have:

  • E26 – regular screw base light bulbs (E stands for Edison btw)
  • E12 – small screw light bulbs. Aka candelabra bulbs.
  • T8/T12 – tube florescent lights

Bulb shapes you probably have:

  • A19 – this is the regular 60W incandescent bulb. Yes, you can still buy these.
  • A15 – this is often the shape used for appliances (refridgerators).
  • PAR20 / PAR30 – if you have track lights
  • R20 – I’ve got this in my range hood, not sure it’s other users
  • T8 / T12 – if you have tube lights
  • C7 – this is the standard Christmas light string bulb

The reason this is important is that lighting fixtures have a design point of the bulb going into them, and you’d be surprised how close those tolerances are some times.

Measuring Light

It’s kind of amazing that for the first century of electric lighting we measured the light of bulbs by the amount of energy they consumed. Given that incandescent bulbs turn 90% of their energy into heat (not light) maybe it’s not so odd. But it tells you very little about what this is going to look like in your home.

The lighting market was so static for so long we could get away with 60W as measure of brightness. CFLs made that more difficult, so everything has markings about the “equivalence”. So a 17W CFL is a 60W equivalent bulb. But with LEDs landing everywhere now the industry is fortunately taking a step back and actually starting to use some real measurements so you can compare things.

There are two critical dimensions of light: color and intensity.

Color

Color is measured by temperature in Kelvins. It’s based on the physics of black body radiation, and largely moves between a red and blue scale. Computer monitors have been using color temperature for enough years now that people are hopefully a little familiar with it.

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Black body” by Darth KuleOwn work. Licensed under Public domain via Wikimedia Commons.

Incandescent bulbs typically are 2700K – 3300K in color. Soft white or Warm white is often how it’s referred to in lighting. Daylight is closer to 6000K and is what’s considered Cool white. If you like your light slightly yellow, stick to the low end here (2700K).

Intensity

Intensity is measured in it’s own standard unit of Lumens, which is actually a perception unit, so it does attempt to compensate for only what your eye reacts to. The whole process of calculating lumens is pretty complicated, so don’t expect to work your way through it. It’s a unit of measure you’ll just have to build new intuition on.

Leaning back on our crutch of “this is what incandecants are like”, here is a handy chart courtesy of Clark Howard:

How Much Light Do I Need?
Incandescent Bulbs

WATTS

Minimum Light Output

LUMENS

40 450
60 800
75 >1,100
100 1,600
150 2,600

Why LED?

LEDs have a bunch of advantages. Honestly, the wikipedia page on LEDs is fun reading if you want the full history.

The top reasons for me were:

  • Energy efficiency: uses about 1/6 the power of equiv incandescent and 70% the power of florescent. This also means less load the electrical in your house.
  • Cool to the touch: you can tell you are’t wasting energy because you can touch the bulbs when on and they are only slightly above room temp. Important for certain applications.
  • Longevity: LEDs are rated for roughly 20 years of use before failure. And it’s pretty clear that’s probably a low ball number. Also failure in LED case is typically they get dimmer by 10%. These are heritage items that might be passed down to your kids or grand kids. Which also means they are not going to generate landfill. Which also also means you don’t need a shelf full of spares around.
  • Near instant on: no delayed ramp up to full intensity like CFLs.
  • No humming: I can hear the CFL ballast humming (though apparently my wife doesn’t notice it). The new silence in our master bathroom was astounding.

The other great thing about LEDs is the actual light unit is this little chip. So while you can get LED light bulbs that retro fit existing fixtures, you can also get fully integrated light fixtures in shapes and sizes that have never been possible before. That’s a lot more extensive than just changing out bulbs, but it opens up a lot of possibilities (more thoughts on that later).

The whole series:

As always, corrections or comments welcomed in the comments here.

Refrigerator Design Challenges

I’ve been going on a tear this week and converting most of the lighting in our house to LED lighting (I am going to write this up in detail later). There are a lot of reasons to change out bulbs to LEDs, and I’m going to talk about one of them here.

GE Stock Lightbulb

This is the stock light bulb in our GE refrigerator. While a little hard to see, it is stamped with 120V60W on the base. It’s an incandescent bulb and sits only a few inches off the top shelf. For reference, the easy bake ovens used a 100W incandescent.

We had noticed that dairy never survived on the top shelf. Eventually we noticed that was because within seconds of the door opening, we’ve got an oven on our top shelf. This is not really what you want inside a refrigerator.

This has now been replaced with a 7.5W led appliance bulb (effectively one of these, though a different brand I bought in home depot). For reference, I burnt myself removing the old bulb even though the door had only been opened for 15 seconds (that’s how fast it gets really hot). With the new bulb there is barely a discernible temperature difference between the top shelf vs. the rest of the fridge.

I do wonder if anyone at GE actually contemplated this issue before the product shipped, or if lighting thermals are the kind of thing that falls through the cracks.

Arduino RGB Testing

Last night I managed to get some more time on the Arduino, getting a basic color rotate working. Youtube video below:

I’m now trying to figure out a reasonable algorithm for generating colors that would simulate the rayleigh scattering that you get at sunset. I think this is going to involve a lot of trial and error to just get something that looks cool. I also need a couple of good turnable pots for dialing in colors. I think I’m going to have to check out The Shack and see what they have.

Things I still need to figure out:

  • The right way to split the 12V in for both the Arduino power and the light power
  • I think I need to add a push button to change modes, and have been thinking about doing color flashes as an indicator of which mode you are in
  • Even with the bias, Green goes bright really quick. I think I need to do some low value analog tests for brightness and calibrate accordingly.
  • The LED strips get a bit hotter than I expected, which I don’t think will be an issue, but is interesting

Overall I’m having a lot of fun with this, and get excited to get an hour or two on it when I get home at nights.