Category Archives: Electronics

My Breadboard Brings All The Boys to The Yard

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When I’m bored on a Saturday, I sometimes like to go to Goodwill and buy a fork.

Just one.

Knives and spoons are also fair game, but forks are my favorite.

Often I’ll take a friend, if I have one handy, and she is the sort who does not immediately hang up when I ask for help buying a single used fork.

Everyone takes some persuading, at first, so I explain that it’s a really a game, with one goal: to pick the single best fork from among dozens or hundreds of random examples of the type. Having someone else along makes the game that much more interesting because, not only do you have to find the best one, you have to agree on it.

The point, besides having fun, is to practice appreciating the infinite variety that even the most mundane objects and experiences offer us. The thing itself costs maybe fifty cents, and if the hunting is good, can become a treasured prize and keepsake. Especially if you mud-wrestle for it afterwards.

My habit of staking out eBay for seemingly boring stuff — AA batteries, pull tabs, empty bottles — comes from a similar place. A solderless breadboard is ephemeral by nature, so most people never really stop to think about whether theirs could be better in any way. As long as it does the job without exploding or giving you anthrax, why waste time thinking about it? Honestly, I don’t have a good answer to that question. But the fact remains that I naturally tend to do so.

The object pictured here is the most amazing breadboard I have ever seen. I bought it simply because it turned up in one of my “boring” eBay searches and I doubted very strongly that I would ever see another like it. I paid twenty-five bucks plus shipping. I will let the photos speak for themselves.

Flameless Hack-o’-Lantern Featured in Popular Science

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Complete "Hack-o'-lantern" and mini breadboard that goes inside

This piece marks my third by-line in Popular Science. It opens the “Manual” section of the October 2015 issue. Besides designing the circuit, writing the copy, and building the solder-free breadboard-based device shown in the photo, I also carved the pumpkin. Fun fact: Halloween magazine content has to be in bed in the summer, when nobody is selling pumpkins. There is, however, a high quality brand of carve-able fake pumpkin, called a Funkin, which is apparently the industry standard for this sort of thing. It carves easily with a special tool which is somewhere between a paring knife and a fine-tooth hacksaw.

I’m indebted to Lenore and Windell at Evil Mad Scientist Laboratories for the two circuits on which the electronics are based. My breadboard is really just a simple mash-up of their dark detecting jack-o’-lantern and solderless flickery flame designs. Their online store remains the best place to buy candle-flicker and other specialty LEDs in the known universe, as well as tons of other cool open-source electronics you can’t get anywhere else.

Here’s Popular Science Projects Editor Sophie Bushwick building the project on camera:

Styrofoam Plate Hovercraft: My Debut in Popular Science

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working-prototype-02-with-battery-and-fans-still

Of course I knew for months in advance that this was coming, but what I did not know, until I actually received my copy of the March 2015 print issue, was that I also got a coverline.

2015-02-27-March-2015-PopSci-Coverline

This project actually started as one of six ideas I sent to littleBits when I began negotiating to develop projects for their Explorer Series kits in late 2014. It was inspired by the well-known “Kelvin” hovercraft activity developed for primary-school STEM educators. There was a lengthy prototyping process in which I tried to produce a workable styrofoam-plate hovercraft using littleBits components; when it became clear that the single 5V case fan bundled with their Premium Kit was not going to be able to lift its own weight, I pushed forward anyway, adding fans and stripping away other components as needed until I got to a reliable power-to-weight ratio. The 5V fans that I used in the final build (Sunon #MB50100V2-000U-A99) are exactly the same part used in the littleBits Fan Bit (though they are deliberately overdriven at 9V).

[vimeo https://vimeo.com/106963508 w=600]

Here is some heretofore unpublished video of the finished prototype in action. On a fully-charged 150mAH NiMH 9V, it will float for about 5 minutes. You can see that it tends to precess in the same rotational direction as the fans themselves; I would like someday to try a similar build using counter-rotating fans to cancel the net torque, but it will have to use bare motors rather than all-in-one case fans, because case fans all turn the same direction and are not, to my knowledge, ever available in the opposite handedness.

Hoverplate Exploded Illo 001

If the torques could be made to cancel, the next logical question is whether they could be modulated to provide steering. It seems likely to me that a four-fan configuration using impellers counter-rotating across the centerline and controlled by a “Herbie” type BEAM circuit with two photo-diode sensors could in fact be arranged, fairly easily, to both float the vehicle and steer it towards the brightest light source in the environment using a “net torque” steering mechanism.

MSE-5: The Weekend Project That Wasn’t

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An elaborate but small hand-assembled BEAM style robot with carefullly coordinated colors in blue and white.

All parts are from RadioShack. Photo ca. August, 2012.

This is a Herbie-style BEAM photovore with a reversing relay. But instead of a bump switch, the “retreat” reflex is triggered by a sharp, loud sound like a clap. It was developed for MAKE’s RadioShack “Weekend Projects” campaign in the summer of 2012; the prompt specified a project that responded to both light and sound. “MSE” was intended to nod at “Mousey the Junkbot,” Gareth Branwyn’s famous Herbie-style build from “The Absolute Beginner’s Guide to Building Robots” (and MAKE Vol 06). MSE-5 was by most standards a failure, coming in three weeks past deadline and well over budget due to persistent line noise problems that would cause the reversing relay to trigger over and over again. I did eventually iron out the bugs, but the final build was much too complicated and never saw use. Still, the finished ‘bot turned out pretty sharp-looking, and I learned a heckuva lot about electronics in a very short time.

Though I can’t necessarily recommend that anyone should build it as-written, a complete PDF of the unpublished Make: Projects MSE-5 tutorial is available at the link below.

MSE-5: A Light- and Sound-Sensing Robot

OCD Bristlebot

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A yellow toothbrush head, with white bristles, that's been cut from the handle. The bristles are on the ground, and there's a layer of foam tape on the back of the head securing a small piece of black phenolic board that matches the shape of the head. On top of the phenolic board are a small pager motor, mounted in fuse clips, a toggle switch, and a CR2032 coin cell battery holder with a battery inside it.

Plastic toothbrush head, fuse clips, pager motor, toggle switch, copper-clad board, double-stick tape, coin cell and holder.

I made this little robot sometime in mid-2014. The motor case, fuse clips, and most of the underside copper layer are grounded, with small “islands” manually cut clear to carry Vcc. The sides and top of the phenolic board are stained black with Sharpie marker, and the foam tape provides a solid interface with a bit of give to accommodate the underside solder points. The toothbrush belonged to my grandmother; I found it in a travel kit in a piece of very old luggage.