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!

Advertisements

Revisited: Bluetooth Speaker

20160804_172458 In the last little while or so, I found myself using the Bluetooth speaker I made last October. There were a few minor things that I wanted to address so I went ahead and made the modifications.

20160804_173243The main technical modification was adding an on/off switch to the power supply. I would have to keep plugging and unplugging the unit which got a bit annoying after a while having to do that almost daily whenever I wanted to use it. It was very easy to do since the electronics are completely accessible from the open underside. I simply cut the positive power line and soldered a switch in place.

20160804_175950The other modification was purely aesthetic. I removed the label and painted it all grey. My original choice was blue but I didn’t have that color paint. Either way, I think it looks good.

It’s always nice to revisit old projects with new techniques and materials. Stay tuned as I’ve revisited another project as well!

A throwback of sorts… The Buzzer Box!

Back when I was around 11, I strolled into a Radioshack and bought some wire, a buzzer, and a battery pack. I had a weird fascination with my elementary school’s fire alarm and wanted to recreate it. Completing the simple circuit by tapping wires together was enough to satisfy me until the project was lost. Fast forward about 15 years later, I’m revisiting the project that started it all.

20160320_125204

This circuit is slightly more complicated than the original, I’d say. I used a 555 timer to get the pulse that would buzz the buzzer on and off at roughly a 50% duty cycle. In the end, I ended up using 9v instead of the original 5v I had planned, but it worked just the same.

20160320_114828

The project was put into this small enclosure. I drilled a hole for the button that is pressed to activated the buzzer alarm.

20160320_115313

Here’s the circuit on a breadboard to test and experiment before soldering the circuit permanently.

20160320_123209

A close-up of the circuit on the perfboard.

20160320_123218

A close-up of my soldering.

20160320_123202

After soldering the components to the perfboard, I soldered the buzzer, battery, and switch into the circuit.

20160320_123905

After some musical chairs with the components, and then some hot glue, everything was set into the enclosure.

Here’s the Buzzer Box in action…

Who needs a life alert when you have this… thing… #diy #electronics #shittyrobots #buzzer #alarm

A post shared by Matt (@mwhprojects) on

It was a simple [and useless] project but I’m the kind of person that likes to revisit the past in ways like this.

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

20160215_085119

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.

20160215_085433

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.

20160215_085601

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.

20160215_090815

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

20160215_092036

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

20160215_093706

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

20160215_095119

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

20160215_101031

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!

DIY Bluetooth Speaker!

20151017_120959

After weeks of waiting, the parts I needed for a homemade Bluetooth speaker arrived. Pictured above are the PAM8403 amplifier board, Bluetooth module (USB powered with a 3.5mm audio jack), and a couple of 3-watt speakers. The power supply is a 5V 2A power supply I had laying around. All of the project materials amounts to roughly $13.

I got the inspiration from a couple of my favorite YouTubers — GreatScott and David Watts. They had much more polished finished products with a good quality speaker and cool enclosure… I had neither of those.

The project itself was simple enough: Break open the Bluetooth module, apply power to it, and then take the audio signals to the amplifier which would drive the speakers.

20151017_122126

Here’s the Bluetooth module cracked open. My original intention was to remove the audio jack and USB plug to end up with a flat board, but the desoldering did not go well as I didn’t have any solder wick. After some failed tries with my desoldering pump, I ended up cutting off the edge of the board with the USB plug, and giving up on removing the audio jack. There were two copper pads near the USB plug that were labelled Vcc and Ground so I used them to apply power instead of bothering the with the pads of the USB plug.

20151017_143630

Wiring it together did not go as simple as I thought it would either. I tried connecting wires directly from the pins of the audio jack to the amplifier board, but it didn’t work. The audio jack was still working with headphones, and the speakers worked faintly when connected directly to the audio jack. (The speakers arrived a bit banged up so I was worried they may have been broken.)

After some time troubleshooting, I ended up replacing the PAM amplifier board (I bought a few, exactly for situations like this) and spliced the included 3.5mm audio jack cable and used that to connect to the amplifier board. I was so happy to hear the power-on tone that the Bluetooth module makes!

20151017_184729

After some playing around with it, I realized that there was only static coming out of one of the speakers so I chopped that one off. I’m not a audiophile by any means so I’m easily impressed… I was pleasantly surprised in the audio quality from these cheap speakers. Even with just one speaker, it can get pretty loud without sounding bad.

20151017_214118

Time to put everything into an enclosure! This was my first time using foam board. If I didn’t use foam board, I’d still be using cardboard. Now that I’ve given it a chance, I can definitely see foam board being my go-to material for this sort of thing. My cuts are a little rough but I learned later on that using a new blade and/or cutting at an angle will give you cleaner cuts.

I used some needles to keep the foam board in place while I used hot glue everywhere.

20151017_222217

Once I was finished putting it together, I printed out a simple nameplate for the speaker.

The Bluetooth module board has a blue LED that blinks rapidly when it isn’t connected, and once every 3 seconds when it is. Honestly, it wasn’t intentional, but my design with raised bottom, which was intentional, worked in the LED’s favor as it gives it a neat glow underneath the speaker. The nameplate originally had a note about how the rapid blinking meant it wasn’t connected, but my printer wasn’t having it…

So that’s it! It only took me half the day from start to finish and I am satisfied with the final product. I hope you’ll take this post as inspiration to whip up your own Bluetooth speaker!

Thanks for reading!

The lamp that WAS meant to be! (WS2812B LED Box)

A little while ago, I was experimenting with a WS2812B LED and toying with the idea of making a basic lamp. Things didn’t work out and the project was scrapped but I still had the internals of it ready on a breadboard so I gave it another go, while taking in some inspiration from the comments on that post which mentioned a product that’s more or less a small table-top spotlight.

20150822_151542

From my previous experiments, I already had a WS2812B LED soldered to some wires. For this project, I used only 22AWG stranded wire. For isolation and to hold things in place, I used hot glue.

20150822_151553

With the LED ready, I started by putting one of my Attiny85 breakout boards onto the perfboard.

20150822_200005

I then completed the soldering of the LED and potentiometers to the perfboard. The potentiometers are all connected to each other by Vcc and Ground. It seems like the connections in between one another weren’t very good as the LED would go wild at times, changing color or blinking for no reason. After some wiggling with the wires, I found which connections were weak and reflowed them.

20150822_202840
… But even reflowing the connections didn’t work. The only thing that did fix the problems was putting force on the connections in a certain way. Once I got it working, I quickly hot glued everything. I know that’s horrible, but, being such a no frills project, I’m not very concerned. After the circuit was completed, I trimmed down the perfboard since the rest of it wasn’t needed.

20150822_204337

The potentiometer and LEDs were all 5mm^2 so it wasn’t difficult cutting out appropriate sized holes for them. I first put in the LED and taped it to hold it in place before adding hot glue.

20150822_204355

After the LED was in place, I fed the power supply wires (female jumper wires) through a hole I cut near the bottom corner of the box. The potentiometers come with a washer and nut so I didn’t need any hot glue to keep those in place. This is my first time using these kind of potentiometers in a project and, even without fancy knobs, I think they look great. They certainly look better than tiny trimpots, which is what I would have used otherwise.

20150822_204657

And that’s it! The placement of the potentiometers was planned specifically to double as a way to lay the box down on an angle.

I hope you liked this simple project of mine. I recently ordered a set of these LEDs for an idea for the next Light Show.

PS. My main website, www.mwhprojects.com, was recently updated!

A look at a Crystal Oscillator Frequency Counter Tester

1A few weeks ago, I had a few crystal oscillators that weren’t working properly so I bought this crystal oscillator tester kit from eBay. It was sort of an impulse buy because I can test oscillators in a test circuit so I didn’t really need this. It’s been a while since I’ve purchased a kit like this so I was excited anyway. The last time I put together a circuit board kit like this was back in my first semester of college!

You can pick up your own here. (Just search the name of it on your country’s eBay if you’re not in Canada.)2The parts were packaged well. Not a single bent component lead.3I admire every circuit board I come across more these days with my work that I do on my own circuit boards. One thing I enjoyed about this board were the wide diameter pads which made it really easy to solder. The board is nice and thick (thicker than 1.6mm I think), and it measures in at 8 x 5.4cm.4After putting this together, it makes me want to start making boards larger than what I’ve been doing so far, which has been bounded by 5x5cm because it’s cheaper to get made than anything bigger. I put in a 9v battery clip instead of the included barrel jack because I never use those.

5Like I said, the soldering was enjoyable because of the size of the pads. I always try to make the pads on my boards as large as possible but it’s usually too tight for space or I’m scared it’s going to come out wrong…
6It works! I tested it with a few good 16MHz oscillators and it’s pretty close, either on the dot or 15.999 as in the image. I also tested that broken oscillator and it jumps around to weird frequencies from 0 to 16MHz.

I hope you enjoyed the look at this kit!