posts tagged with the keyword ‘arduino’


NoiseMaster VII

The next noisemaker in this ongoing and seemingly never-ending series is one of my favorites. This time we’ve done away with any sort of real “enclosure” and everything is just mounted on a board. We’re also using a real Arduino on this one. It’s an Arduino Nano, which you can find online for approximately $3USD nowadays. It’s quite a step up from the ATtiny85 chips used in many of the previous noisemakers.

NoiseMaster VII

Even though we moved away from an enclosure on this one, we still have to mount things, so why not model and 3D print some things? We’ve got a button and a potentiometer as our controls, and each one has a small printed part to allow for mounting to the board.

NoiseMaster VI

Again, the best thing about 3D printing in this process is you can create exactly what you need. With bits of scrap wood you’re constantly cutting and drilling to get things the right size. With designing your own parts, you make what you need. Here’s a piece that holds the button I had and has a small hole near the base to allow wires to come out.

NoiseMaster VI

This piece holds the potentiometer. It’s the correct thickness to allow the potentiometer to fit and the shaft to go through the hole. The holes for mounting screws are also the exact dimensions needed to work with the #4 screws I had. Making things fit together is about 90% of making.

NoiseMaster VII

Here’s a neat trick. Remember all those hard drives we took apart? Well, I saved all the magnets, and they’re handy to have around. Since they are attached to pieces of metal with mounting holes on them, I screwed one down to the board…

NoiseMaster VII

…and it’s perfect to hold a speaker in place. Really. That speaker ain’t going nowhere! You can pull it off, but it’s on securely enough that it takes some force, and it’s not going to fall off or get knocked off easily.

NoiseMaster VII

The Arduino Nano is on one of my Nano BOB boards. I use these to allow screw terminal connections to a Nano. (I really should get these listed on my Tindie store one of these days.) Power is provided by a Mini USB cable, and yes, there’s two 3D printed standoffs under the PCB. As a bonus, the wires used were pulled out of some phone wiring I rescued from a dumpster.

NoiseMaster VII

I like this one so much, I may be reusing some of the parts in another build I’m working on. Hopefully I can post about that in the coming weeks.

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



It’s been a while since Decagon Light (Part II), but we’re here with Part III! Thanks to Jason we (mainly he) finally got around to do the CNC work for this monstrosity. Becky then wired it up while I worked on the programming. (Thanks, Brinn Labs!)


Below is the small prototype again…

A post shared by Pete Prodoehl (@raster) on

Besides adding some new patterns, I modified the code so you can use any consecutive pins. For the LEDs I use pins 1 through 10, but for the lamps we’re using 2 through 11. (Don’t ask why.) I also added an logic flipper, because LEDs and relays work opposite, HIGH is LOW and LOW is HIGH, depending on which you are using, so yeah, a lot of the code writing was just to deal with the differences between two version of this thing. Anyway, I squashed the last bug today, so it’s all good. (I think.)

And here’s a short video of it in operation. There’s still work to do, but we’ve made great progress in the last two weeks. (And yeah, I really wanted it done before Maker Faire, but didn’t quite hit that deadline.)

You’ll notice the design of the lines changed a bit. It’s still a decagon (a 10-sided polygon) but it’s no longer a 9-simplex. It’s almost a 5-orthoplex, but not quite. If you can figure out exactly what it is, let me know.



A large part of the Power Racing Series is Moxie. Moxie is best described as, being awesome. The crowd gets to vote for your car using the Moxie Board. Each button press equals a vote. Being fast is one way to get points, but another way is by being awesome… so, Moxie.

Above you’ll see a photo of the official Moxie Board used by the series. Since we also had a PPPRS race during Maker Faire Milwaukee, which overlapped the race in New York, we had to build our own Moxie Board, so here’s what we did…

The Moxie Board

It looks fairly similar, but it’s a bit smaller and lighter than the original, and it’s got 24 buttons instead of 30 (though I believe the original was recently expanded to have that 30 buttons. Who knew there’d ever be that many cars in a race!)

I got some Coroplast from Midland Plastics for super cheap, and they didn’t have any wide enough, so the black strip running down the center is gaff tape used to hold two pieces together to be wide enough. I then found some scrap wood in the shop at work which was long enough, but too skinny to be used for anything else, and built a simple frame with some small blocks of HDPE in the corners to hold it all together. (I was told the reduced weight of this Moxie Board was a big plus.)

The front is screwed into the wood frame, and the back is held in place with some VELCRO┬« hook and loop so we could open it to get to the electronics…

As for the inside and the electronics, while the original uses an Arduino Mega with a Bluetooth module to send real-time updates to Patrick’s Android phone which is running some special app, I chose to do it differently.


I’m using a Teensy 3.5 which has plenty of input pins and a built-in MicroSD card slot. The way it works is simple, each button represents a number from 1 to 24, and when pressed, the Teensy gets the value of every button, with the ones not being pressed equal to 0 and the one being pressed equal to 1, and then writes it to a file called MOXIE.csv. When the race is over you just put the MicroSD card in a card reader and import the CSV file into a spreadsheet and grab the last row. (Hopefully your spreadsheet is set up with the names of the cars in the corresponding columns.)

In testing, this all worked fine, but obviously the real world had to come along and crush my hopes and dreams…


Failure #1: Because the Teensy is a low power device, it doesn’t draw much power from the USB battery pack we were using. I’ve seen this before, so I use a battery pack with a built-in LED “flashlight” that stays on, as long as you press and hold the button when turning it on. I told this to two people, but forgot to write instructions to put inside the Moxie Board, so there’s a chance this was not done properly and power was lost. (There is an indicator LED that lights up when a button is pressed, but not a “POWER ON” LED which would have helped… maybe.

Maybe Failure #2: It could be that my code isn’t quite right. I do not have the most recent code that the official Moxie Board is running, but I have an older version that may be close. My code is a little different, but should yield the same results… I think. This is worth checking on.

I also do not have a good way to attach Moxie Labels, so they are just attached with tape or Hook and Loop for now. Ran out of time for anything better. :/

One more note! In the photo there’s a bunch of green wire and LEDs attached to the front of the Moxie Board. Those were added for the night race. All the actual wiring for the Moxie Board is located on the inside.


I’ve heard of one other group working on a Moxie Board that will use a Raspberry Pi, which I thought about doing as well, but ended up choosing a Teensy instead. As we add more races, we’re going to need more boards, so I’m hoping we see more ideas and eventually come up with even better ideas. (Note that I wanted to stay simple because simple gets done while over-complex builds, while fun, don’t always get finished, or work properly. But then, who am I to talk!?)


Arduino - The First Sketch

The Inventors & Entrepreneurs Club of Kenosha & Racine invited me to give a talk last year but I was busy teaching PCOMP at UWM so I couldn’t make it, but I offered to come during the summer and we scheduled August for me to visit and talk about the Arduino microcontroller.

A few people were familiar with the Arduino, and one or two had even used them before, but for most people this was an introduction. I covered a bit about what the Arduino is, and what it can do, and how you might use it for prototyping a product.

I updated the Presenations page and added the Welcome to Arduino slides, and noticed I hadn’t given any presentations in 2016, but then I remembered that I had a class full of students twice a week during that time and was pretty much presenting constantly. Life is weird sometimes. (And actually I did do some presentations while at UWM, so maybe I’ll dig through those and post them.)



I started this project with a goal in mind: test microswitches. Specifically, test the brand of microswitch that I chose for an exhibit I worked on last year. When I was younger, my dad used to have a subscription to Consumer Reports and I remember years ago reading about how they tested things, like using a machine that opened and closed laptops repeatedly to see how many times it could be done before it broke or wore out. One of my goals is to do that sort of thing, but with things we build for exhibits. This is a start. (And yes, I’ve considered just buying/building a robot arm to do these things… I may still do that!)

Meanwhile, since I’m 3D printing again (a lot!) I figured I’d design and print the parts for this machine. Not all the parts… some parts are scrap wood, and (in a recent version) home-made recycled HDPE. The first iteration was a total hack job, and it worked. Sort of. I get in this habit of trying to do press-fit parts, but then I remember that’s a bad idea, so… upgrades happen.


The first version used a PLA plastic arm. Eventually it started to scrape and wear away, and squeak a lot. It was annoying. (Bearings got added to a later version, along with a proper set screw.)


One thing I found out about the cheap microswitches is that the metal arm would bend, and then stop pressing the switch. That’s no good (but good to know.) Then I found times when the switch just wouldn’t trigger the Arduino to advance. Switch failure after just a few tens of thousands of presses? Maybe.


I also had Arduino problems! At some point the cheap eBay Arduino UNO clone from China gave up the ghost and just stopped working reliably. Then I could no longer upload code to it or connect to it at all. Replaced that too!


I also played around with the switch angle… as demonstrated in the above and below photos. I also considered a spring-arm sort of thing the switch could ride on to allow some flex, which would be interesting, but probably less of a real-world test. Maybe.


Here’s a video compilation of some of the testing from early on. This is when I actually thought I could just slap something together and it would work reliably. I’ve since been proven very wrong. I’ll be writing more posts about the changes this machine has gone through and where it stands today. In the meanwhile, if you check out my Instagram or Facebook account, I often post in-progress/sneak-peek photos and short videos.

Stay Tuned!

« Older Entries |

buy the button:

Buy The Button