Revisited: Desk Lighting Project (v3)

For the past couple of years, I’ve been experimenting with adding LED lights to my desk. The first time, I basically scattered 5mm LEDs all over my desk. The second time, I used a decorative LED string of lights. Now, I’m onto 12v LED strips! For this revisit, my workstation next to my computer desk will also get some lighting too.

IMG_20160810_191527I took the switch enclosure and enlarged the hole to fit two new switches. I used hot glue to fill any gaps and black paint to make it blend with the color of the enclosure. There’s something about this process that’s just so satisfying!

IMG_20160811_154919The switches basically open and close the positive connections of the two LED strip segments. All of the grounds are connected together. It’s a very simple circuit that did not take very long to put together.

20160811_163944The longest part was organizing the cables and strips. The switch panel is in a lower position so it doesn’t exactly blend in quite as well as it did before. The reason that it’s so low is that the cord for the power supply is much shorter so it wouldn’t comfortably reach the power strip outlet.

20160811_163928 The LED strip is much brighter than any of my previous attempts at adding lights to this desk.

20160811_163936This is my workstation with the LED lighting. This has actually had the LED strip installed for a while now but I was using the lab power supply to power it, which was noisy. It had a hand in motivating me to get this project done.

20160811_172920My battlestation’s getting better.

Thanks for reading!

Desk Lighting Project v2.0

Two years ago, I hooked up some 5mm LEDs all around my desk to illuminate parts of it. Looking back at that set up, it looks very clumsily done. Now that I have better tools and materials (even some salvaged from other things!), I thought I’d give it another shot.

Materials

  • String of lights from a battery-operated product, which I had previously used in another project.
  • Switch, which was taken out of a broken power bar.
  • 5cm x 8cm x 3cm enclosure.
  • 5V 2A rated power supply.
  • 8-Ohm 1W resistor.
  • 22AWG solid-core wire.
  • Heat shrink.
  • Hot glue.

Putting It Together

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The switch’s back measured roughly 26cm by 13cm so I drew the outline of it on a piece of paper and taped it on the box.

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After locking the box into a vice, I drilled 1/8″ holes on the four corners… They weren’t exactly precise but it’ll work.

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I then used my rotary tool with a cutting wheel attachment to cut out the rectangle. The excess material becomes brittle which makes it easy to clean up.

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On one of the sides, I drilled two holes which the power supply and light wires would pass through.

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I brought the box to my soldering station to put together the simple switch circuit inside of the box.

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The switch interrupts/completes the positive connection. A resistor limits the current for the LEDs.

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After soldering and shrinking the heat shrink tubing, I applied some hot glue to keep exposed connections insulated and in place.

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I screwed in the back plate of the enclosure and then hot glued the box to the side of my desk. The string of LEDs are taped behind the decorative wooden piece above my computer monitor.

The switch works like a charm and, as simple as it is, is really one of my more polished completed projects. I hope I can say that for every project moving forward!

Thanks for reading!

Desk Lighting Revisited

For a while now, I’ve been wanting to do a revisit to the desk lighting project I did a long while ago. I never used the colored lights along the side and I was never satisfied with the amount of light from the main white LEDs. Sometimes they’d be too bright for something I was watching. I decided to use one of my Attiny85 Breakout boards to have a potentiometer dim the white lights. I removed all of the other lights.
IMG_0708The controller went from this…IMG_20140811_141736…to this. The positioning is a little clumsy at the moment but it’s still smaller than the original board. I soldered the 10K potentiometer to a small piece of perfboard which has wires that connect it to the breakout board (soldered). I wish I had a larger knob potentiometer because it’s a little difficult to turn this one without a screwdriver. It works well enough for me so it’s not a big deal. It took just a couple of minutes to program and get it connected to the existing lights. It’s nice to know that the first PCB working wasn’t just a fluke.IMG_20140811_131146In other news, I was going to make a fume extractor but the carbon filter I ordered on Amazon has mysteriously gone out of stock even though it originally said I ordered the last one. Oh well, the fan by itself is good enough for getting the smoke out of my face. I removed the original wires and connector and soldered a 9v power supply directly to it. What I didn’t think of was that the large 9v power supply has a large wart that covers the remaining plugs on my power bar so I don’t have anywhere to plug in the iron… so the fan is powered by a plug across the room. I guess that’s a perk of having the smallest room in the house.

I have some exciting plans coming up but I’m still working on a few things before I share. Thanks for visiting!

Shelf Lighting System

After the nice result of the Desk Lighting System project, my brother wanted me to do the same for some shelves in the basement. It quickly turned into a larger project than I was anticipating. This was honestly one of the most stressful projects I’ve worked on in a while as I spent 7 hours non-stop for two days getting it up. The lights we got was a 5 meter white LED strip. I had to go back the next day for two reasons: I bought the wrong power supply (had AC output), and I researched more and saw I would need a mosfet transistor (some explanations on this later).

IMG_0738The first day was literally spent cutting the strip and soldering them back together. It took a long time because the pads on the strip are really small when you cut them so they broke off or the solder gave me a hard time by refusing to flow on the pad. Once that was done, I taped them on all of the shelves. That was all of day one.IMG_0733Day two was another frustrating mess. I got the circuit working using an Arduino Uno board. The final project would have a standalone Atmega328p circuit and a voltage regulator. Before I move on, I want to explain exactly what the Atmega chip is for since I didn’t use it in my last lighting project.

My brother requested a dimmer. To do that, I’d need to use the PWM, or Pulse Width Modulation, pin on the Atmega microcontroller. Basically PWM is adjusting the duty cycle of the output signal so it changes the intensity of the light as we see it. To get a dimmer light, the duty cycle is decreased, or the time on becomes less than the time off in one cycle.

To make things more complicated, the LED strip runs off of 12v, which cannot be supplied directly to the Atmega chip. That’s where the voltage regulator and  mosfet transistor comes in. The voltage regulator is a constant 5v regulator that is required for the microcontroller. The mosfet transistor is used in this case as a switch to open or close the ground connection of the LED strip. The positive connection of the LED strip goes to the 12v source. When a signal is sent to the mosfet [gate], the “switch” closes, turning the lights on. PWM still works as it’s basically opening and closing the switch really fast.

Now back to the pictures…IMG_0735I tried soldering it together. That failed. I don’t know if it’s a failure of connecting it properly or if it was because I had a wrong capacitor (which I discovered after, when I decided to just breadboard it).
IMG_0736So yeah, I took the easy way out on this one. My main worry is that something is going to fall off because it’s mounted sideways. I taped as many connections as I could so it should hold up. I’ll probably keep a close eye on it for the next few days to see how it works out in use… even though I don’t want to. I’m exhausted from this project.

IMG_0737The switch and dimmer potentiometer are solid in place. And yes, it’s another food container.

IMG_0732The final result.

Good riddance… I mean, it’s pretty amazing that everything came together in three days, but the stress was intense trying to get it to work. I have a fear that something will give.

On to the next one.

Desk Lighting Project: Complete!

So the Desk Lighting Project is complete! I took some video along the way so I don’t have any construction pictures. I’ll quickly run through the process though.

The first thing to do was prep the power supply, the 5V one I mentioned in my last post. That meant chopping off the plug on it, stripping the wire, then joining it to some 22-gauge wire using a butt crimp.

The next step was soldering the LEDs to resistors. Each LED color is grouped in pairs, including three pairs of white LEDs for the main area. The white LEDs were also soldered together in a string.

The last step involving soldering was setting up the DIP switch to control the different colors.  There are only four right now, but it is expandable. I just have to solder on a couple of more small wires if I wanted to add a new color. From the DIP switch, the LEDs are connected using jumper wires.

The last step was simply taping the wires and LEDs to the desk. It’s not quite as discrete as I was hoping but, in the end, it kind of looks cool. It makes me desk look less boring.

IMG_0722This is the final positioning of the DIP switch control.IMG_0725This is how the wiring of the white LED area looks. There’s a little extra wire but the tape is doing a decent job keeping it under control.IMG_0724Not quite discrete, but it’s kind of cool looking.IMG_0720I can’t seem to get a good picture. The red LEDs are not quite as bright as the rest of the LEDs on the desk but it’s still fine. If you look at the desk straight on, the LEDs look kind of silly. It looks just how I was expecting it to from where I sit at the desk, though.IMG_0716This is the best picture I could get of the view I have. While I was taping everything to the desk, I was getting disappointed because things didn’t look quite right as it was moving along. In the end, I’m really happy with it.

The Atmega chips didn’t come in today so the name tag project can’t join the rest of the LEDs just yet. Like I said, I did some video recording while building this project. I hope to sort through all that by the end of the weekend.

Decisions

While I wait for the Atmega chips to arrive for the LED name tag project, I’ve started to think about the desk lighting package. Pretty much the only problem I have is the power supply.
IMG_20140219_101931I have one 3-AA battery holder with a switch and a few 9v battery holders (no switches on them). I don’t have any more batteries. As I mentioned in the initial post about this project, different areas of my desk will be lit with different colors. I’m going to use a DIP switch so I can turn off areas of the desk individually. With the DIP switch, I can use one of the switches as a power supply switch. That means that I don’t necessarily have to use the 3-AA battery holder with the switch already on and I don’t have to find a switch for the 9v battery holder. It all comes down to what batteries I’ll go out and buy. To be honest, I’m starting to lean toward just buying a plug for this project. I’m broke so I can’t afford a money pit that would be buying new batteries all the time. I’m going to Sayal soon (probably the weekend) so I’ll look out for one there.

Thanks for reading!