posts tagged with the keyword ‘sound’



In our introduction post I mentioned NoiseMaster 3000 and all of the noisemaking devices we built. Well, here’s another one in the series.

While I used wood for the first one, I chose MDF for this one. MDF has some nice qualities, like being smooth and consistent in surface and size, but besides all that, it’s terrible. Actually, I should say that I’m terrible when it comes to working with it. It’s not like wood, which is forgiving, and I seem to split MDF whenever I use it. I find it annoying, so why not work with it for a project that doesn’t matter that much, so I can try to improve my skills a bit. Good idea, right?


This one again makes use of an ATtiny (I have like 20 of them) and I sort of liked this design when I built it. You’ll notice in the photo above that the screws holding the speaker in place are at a weird angle. That happened in transport, and was not planned. They were actually straight when I built it, but being piled in a bin with a dozen other noisemakers and other things caused a little damage.


You can barely see it, but this one introduces something that will show up in future posts… 3D printed parts. It’s just the standoffs in this case, since I used all the laser-cut standoffs for the last one. Again, all electronics and wiring are exposed, by choice.


I used a lot of screw terminal blocks, typically for power input (though sometimes for speaker output.) Like anything you make, if there’s a chance someone besides you might use it (or if you forget things) add labels! I did not add the ‘+’ and ‘-’ to this, as I know that when I use two wire colors the darker one is always ground and the lighter one is always positive. Maks and Dustin didn’t know that, so they traced the symbols from the PCB and added the labels.


This one once again remained pretty raw. I left the MDF as-is, and did not paint it or otherwise do anything to the surface. I was still just focused on building things quickly. (Don’t worry, that changed a bit as I built more of them.)

This is just one post in a series about noisemakers. Check out the other posts as well:



Around the end of 2016 I got some PCBs made that would hold ATtiny85 chips, and I used them in a sound installation. I was trying to figure out how I might reuse the piece(s) for Maker Faire Milwaukee, but I didn’t want to hang things, and I didn’t want to do the same thing again…

After I made SpringTime4 I thought about using the ATtinys in various noise-making devices, and so the journey began. (I also convinced Maks to join in and the idea for NoiseMaster 3000 was born. Oh, and along the way we recruited Dustin to join us.)


I started digging up all the speakers I could find, and grabbed lots of wall warts from Milwaukee Makerspace, and I’ve always got scrap wood on hand, so I started building. At first I just slapped things together fairly haphazardly, but as I built more devices, I started making design choices. (You’ll see these in future posts.) In this post, we’ve just got a simple noisemaker. You press a button, it makes noise. (One of the criteria we set was that everything would be momentary, so no on/off switches. Sound could only be activated temporarily, so no one could turn everything “on” and then walk away. Sound should only be present when a person was engaged with it.


In nearly all of the noisemakers I built, I chose to keep the wires and electronics exposed, or on display, as it were. If I used enclosures, they were typically open on multiple sides. Speakers were almost always visible. I didn’t stray too far from that aesthetic as I built things. Most of the buttons provided power to the unit, which started the noise, though later there were a few that used the button to enable the speaker. A subtle difference most people would not notice, but if you did, you probably know how microcontrollers work. :)


I started working on the noisemakers in June, and thought that would leave plenty of time to make a dozen before Maker Faire. I came pretty close too, and along the way ended up doing some interesting things (at least I like to think so.)

I plan to write up posts showing each noisemaker (hence the “Part I” in the title of this post.) I’ll include photos and a short video, and notes about construction.

Enjoy the Noise!

This is just one post in a series about noisemakers. Check out the other posts as well:


I got into Processing when I saw that it was a way to interface my desktop computer with an Arduino. Since then I’ve been exploring Processing more and seeing what it can do.

The latest excursion has been into audio, and I found a library called minim to play with. Download it, unzip it, and drop the ‘minim’ folder into your ‘libraries’ folder in your Processing folder, and you’re ready to go. Here’s my first experiment.

There’s an example for AudioInput which shows audio waveforms, so I grabbed the example and modified it slightly, I mainly twiddled the numbers a bit for a larger display.

Audio Waveform

Here’s the (slightly modified) code. (1280×800 being the screen size of my MacBook.)

 * WavyLines.pde

import ddf.minim.*;

Minim minim;
AudioInput in;

void setup()
  size(1280, 800, P3D);
  minim = new Minim(this);
  in = minim.getLineIn(Minim.STEREO, 1280);

void draw()
  // draw the waveforms
  for(int i = 0; i < in.bufferSize() - 1; i++)
    line(i, 250 + in.left.get(i)*150, i+1, 250 + in.left.get(i+1)*150);
    line(i, 550 + in.right.get(i)*150, i+1, 550 + in.right.get(i+1)*150);

void stop()
  // always close Minim audio classes when you are done with them

This code (at least on Mac OS X) runs and expects the sound input to be the built-in mic on the MacBook. This is pretty fun, and my daughter (who plays the trumpet) had a good time making all sorts of strange noises and watching the waveforms that were generated. If you export it from Processing as an application, you can run it full screen with no menubar, etc.

While the mic input is fun, you can also build yourself a little audio visualizer that reacts to what audio your computer is playing. There’s a bit in the manual about Setting the System Mixers, but I just went the Soundflower route here.

Once you’ve got Soundflower installed, you can set up your audio routing…

Sound Out
Sound In

Here’s my sound output and sound input settings in System Preferences.

Fire up Soundflowerbed, and then choose a song in iTunes and our “WavyLines” application should respond appropriately.


Here’s what you should get… well, depending on the audio playing. Maybe I can team up with the guys in the Handmade Music Group at the Milwaukee Makerspace and come up with some ways to enhance this into something even cooler.


Recorded near Alterra Foundry on 1st Street, this captures some of the sounds of traffic on an August night in Milwaukee, Wisconsin.

You are free to use the file under the Creative Commons Attribution License. You can find it at or, or download it directly.

| Newer Entries »

buy the button:

Buy The Button