Stienman's stuff

Not necessarily a commitment to create every day, but hey, who knows. I made it through nanowrimo a few years ago, how hard can this be, right? Right?

While I'm posting this today, I created the device last night in an hour or so. It's far from complete, but the basic idea is shown:

A distance sensor, microcontroller (arduino in this case) and speaker allows one to play a note corresponding to how far their hand is from the sensor. Similar to a Theramin, but not as annoying as this sticks to notes on the pentatonic scale, so there is no discord as the player switches from note to note.

Still need to make it easier to play (most of the notes are crowded near the sensor) and add a volume control (using another distance sensor).

Idea given to me by a volunteer at the Ann Arbor Hands on Museum.


Staff member
Neat. I've been meaning to get an Arduino and geek out. This is a cool idea.


I think we have our bat cave gadgets engineer
I've been helping someone complete their Daft Punk replica helmet. After some effort I finally got the circuit boards in yesterday, assembled all the fiddly bits onto one of them, and wrote a bit of software. I was rewarded with blinking lights - and honestly, there aren't many rewards better than blinking lights:

I'll have to come up with a few more animations and assemble another one to hand over to the client so they can play with it. I haven't received any guidance on dimensions and layout, so this board is primarily a prototype to allow me to test the design and create animations.
Sandbox with integrated lid/bench:

We had an old sandbox that was just 4 five foot boards screwed and set on a sandy part of our backyard, with added play sand from the hardware store. While treated lumber has its place, I don't want to use it in the garden or where my kids will have regular contact with it, so the sandbox lasted about three years. During that time it became was also occasionally used by cats, which was less than ideal. Due to its alternate uses I've been reluctant to build another one. Tarps are annoying, collect water (breed mosquitos), and no one ever puts them back on. Prefabricated plastic ones are too small, too shallow, and also tend to collect water.

My wife wanted to have another one, though, and wanted it before the birthday of boy #6, who is about to turn two, and is currently really enjoying digging up plants in the garden. After a few days research she found this:

So I supersized it and made one:

Still need to dig out the center another half foot and add a bunch of sand, but I'm pretty happy with how it turned out. The bottom is cedar to avoid rot, and the top/bench is pine (well, SPF anyway) which won't rot as quickly since it's not in the sand/dirt. We'll probably paint all the pine anyway. It's modified a bit - the whole thing is 6'x8', but the interior box is only 5'x8'. There are angled cuts on the outside for the bench supports to rest against, and half the bench is outside the box, which means there's only six inches of sand under the bench, rather than a foot. Uses less sand, and there's less area to collect leaves and other detritus.

I ended up changing the design after purchasing wood and hinges. Rather than two 8' benches I ended up cutting them in half and having four smaller 4' benches which should be easier to open, but I was 3 hinges short, so I still have a few hinges and boards to add to the far side of the box. It's usable as-is now, though.

Cost about $160, and I spent about 8 hours total building it.
That's really awesome. Would you be able to provide a list of materials/plans? I think that'd be something my sister's boyfriend and I could build for my niece and step-niece.
That's really awesome. Would you be able to provide a list of materials/plans? I think that'd be something my sister's boyfriend and I could build for my niece and step-niece.
Fortunately for both of us, I don't have to write up plans. Someone on pointed out that the design isn't new, and plans are available for free online here:

Mine is slightly different, mostly just larger, but let me know if you have any questions about the differences.
Someone contacted me about my theremin I posted above, and asked if I could make an instrument quality version with multiple scales, keys, octaves, and a few different waveforms. So I tinkered with that yesterday and was able to do this:

It has some severe problems, as you can hear. The harmonics and beat frequencies are due to the fact that I'm only producing sound at a 5kHz sample rate and 8 bits. Also there's a ton of jitter due to the way the analog converter is set up. I could fix some of those things with a great deal more time, but I can instead purchase a more capable microcontroller for less than what I charge in an hour, it'll save me several hours, and I'll be able to run it at 44.1kHz with 12 bits of resolution with no jitter, a significant improvement. And this will require very little additional time, allowing me to spend time on the scales and keys, rather than forcing a difficult task onto a limited microcontroller. I enjoy trying to make limited hardware perform exceptional tasks - it's a fascinating puzzle - but it's very time consuming and I can't get it to them before their next concert if I'm fiddling around so much.
Got the new hardware in for the theremin project, and now the hardware is (nearly) complete and sounding good:

My client has an antique (ish) radio box he's going to put this inside, so the case I'm using (discarded light fixture) is merely for my convenience in keeping the knobs in order and easy to manipulate.

It'll also make it easier to show off at the local geek show'n'tell (gotech ann arbor) Tuesday evening. Hopefully I'll get a few scales and keys in there, and maybe the continuous (ie, more like a theremin without discrete note steps) mode prior to the meeting.

Anyway, barring any difficulties I hope to ship this to my client early next week. He chose my half rate, which I offer if clients don't require exclusive rights to the work produced, and this is an interesting enough project that I may document it, make it open source and/or kickstart it.
Here's the final demo video of the theremin for this client:

Hopefully he has no further changes so I can ship it this week and get the rest of his payment. He hasn't yet chosen the exclusive licensing option, and I have a few other people interested enough in it that I'm considering creating a different version for sale and/or kickstarter. I doubt it will sell much, but I believe there are a few artists that would like one.

Anyway, fun project.
I'm looking at both for other projects. They have very intriguing possibilities, and if inexpensive could be more interesting than the raspberry pi. The galileo doesn't have HDMI out, though, which limits it a bit. However I expect the TRE to be more power hungry.

Would be nice if they really were cost competitive with the pi. Still, $60 for the galileo isn't bad. Hopefully the Tre comes in low as well.

Don't forget the Yun is already available, has linux onboard, and ethernet, wifi, and the wifi can act as an access point. It runs an open source wifi router distro.
I've mentioned here and there about a project I recently worked on which used nearly a mile of LED rope lighting and a custom light sequencer, but couldn't give any details as to what it actually was.

It's an air hockey rink big enough to rollerblade on. The puck rides on a cushion of air, allowing for significantly faster puck travel than in an ice hockey game. Doesn't need tons of refrigeration, can be used outdoors in the summer, and has an underfloor lighting system for indoor, and outdoor evening play.

I'm not involved in the kickstarter, but in it you can see the prototype I worked on:

Since they finally started the kickstarter for the next prototype, 17 time larger than the prototype I worked on, I figured you might be interested in knowing what it was I was talking. All the filmed shots of the 24'x40' rink shows the underfloor lighting system I designed, built, installed, ripped up, and reinstalled with brighter lighting due to changing customer requirements. It uses standard stage lighting dimmers with a custom arduino controller I developed for it.

They asked me to help them build the 200'x90' regulation size rink they are kick starting now, but I've declined due to time constraints. I did a lot of the pre-design work, though, and it's massive, should be amazing assuming they can get someone to build it for them in a matter of weeks...


Anyway. Blinking lights, thought you might get a kick out of it.

Also, I have a half mile of incandescent warm white rope lighting to sell, send me an offer... :facepalm:
Last edited:
That's very cool!

What is needed now is an automatic over-easy egg cooker so he gets fresh eggs when he wakes up in the morning.
I made a rough thermal grill proof of concept:

Museums and educational institutions should be interested, so I'm doing a kickstarter this summer for larger, more complete versions. Should be interesting!
I wondered what you had been up to. We haven't seen you much.
This is what you've been doing? Building torture devices?

The torture market has untapped potential, but mostly I just like making odd things.
Okey dokey. I've not only made a web page, but spent a good chunk of time making an animated 3D rendering of it so people who want to make their own understand how it goes together. Since I made the rendering, you must look at it.


The webpage is if you are so inclined. It has more pictures and video. Feel free to freeze frame when my face looks funny and add derp text.
In the last 24 hours the video has had over 6,000 views, and the webpage has been visited 400 times due mostly to an article on One of Make Magazine's blog contributors is creating a writeup for it as well, hopefully that'll go up in a day or two.

Still, out of those thousands of people that have viewed it the video and hundreds who've viewed the website, the website has only collected 4 emails of people interested in more information.

This is not going to be a productive kickstarter.

I wonder if I need to focus more on the "Dune Pain Box" aspect of it and less on the sciencey "thermal grill illusion" aspect...
"Got a bunch of peltier coolers lying around? Have I got a project for you!"

In 2014 we moved, I mounted the projector to the ceiling, and we bought a decent surround sound receiver. Since that time the receiver and all other entertainment stuff has been sitting on a too-large table, within easy reach of the toddlers, with difficult to get to cables and wires.

Today I finally made a little two shelf corner entertainment center for it. The bottom is for the bluray, tv tuner (projectors don't have tuners), and game console. The top has a swivel/sliding mechanism which I salvaged from an old entertainment center, meant to hold big CRT TVs. I added a bar and some bolts strategically located so when the swivel/slide mechanism was pushed in, it lined up with the front of the shelf, and when pulled out it rotates the receiver a little over 90 degrees so the back is easy to access. The cords and wires are then zip tied to the bar so you can pull the receiver out without worry over stressing a wire or pulling out a connector.

Used junk wood from an old shelving unit, so the only thing I purchased for this was the spray paint. Took most of the day, but it's done and we've recovered a lot of dead floor space in that room, which is good 'cause we've got a lot of people to fit in there when we're watching a movie together.

It's functional, but it doesn't look good. Visually unbalanced, too top heavy. I'm glad I used free materials and didn't waste good hardwood on this design. I'm probably never going to get around to upgrading it unless I add a lot more equipment, but it does what it needs to do, and lives in a dark corner of a dark room anyway. Given the size of the receiver and my desire for easy access I'm not sure what I would do to fix the unbalanced look anyway. Something to mull over the next few years I suppose.


Steve Hoffman forums or Audiokarma could give you tons of suggestions. Wanted or not. ;)
A coworker and I are building a tesla coil. Even though it's badly tuned and not fully assembled, we were able to generate an arc with it, so it's already generating at least 60,000 volts:

Here's what it looks like right now:

[DOUBLEPOST=1464988277,1464988217][/DOUBLEPOST]That's about half a kilometer of wire on a 6" pvc pipe, with the bottom coil upside down so you can't see the copper primary coil.