Air Quality Sensors In Every Classroom

June 18, 2016 by Bryan Cockfield 4 Comments

One of the first electronics projects for the aspiring hobbyist is wiring a sensor of some sort to a microcontroller, and then doing something useful with the new information. [Brock] has taken this type of gateway project and turned it into a way to get his students involved and familiar with electronics. His take on an air quality meter accomplishes both of these goals, and hopefully helps turn all of his students into the next generation of hackers.

The bill of materials is pretty straightforward. Instead of the go-to Arduino, [Brock] has gone with a Particle Photon which has the added benefits of various wireless connectivity options. The air quality sensor is a Shinyei PP42ns which interfaces easily with the Photon. The only thing that might be out of reach of most public high schools (at least in the United States) is the 3D-printed enclosure, although if you have access to one, [Brock] put the files on the project page so anyone can use them.

Of course, we’re big fans of projects that get students involved in anything beyond standardized tests, and this project goes a long way towards teaching students more than how to pass a test. There are many videos and instructions on the project page if you want to try this on your own, but if the cost for the materials is the only thing scaring you off from doing this in your own classroom there are a few other options. You could use ATtiny chips, or try a different style of sensor, or maybe just try out a different project altogether.

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Life-Size Vu Meter Gets The Party Started

June 13, 2016 by Bryan Cockfield 5 Comments

There’s nothing better than making a giant version of one of your hacks. That is, other than making it giant and interactive. That’s just what [Est] has done with his interactive VU meter that lights up the party.

The giant VU meter boasts a series of IR detectors that change the colors and modes of the meter based on where the user places their hands. The sensors measure how much light is reflected back to them, which essentially function as a cheap range finder. The normal operation of the meter and the new interactivity is controlled by a PIC16F883 and all of the parts were built using a home-made CNC router. There are two addressable RGB LEDs for each level and in the base there are four 3 W RGB LEDS. At 25 levels, this is an impressive amount of light.

[Est]’s smaller version of the VU meter has been featured here before, if you’re looking to enhance your music-listening or party-going experiences with something a little less intimidating. We’ve also seen VU meters built directly into the speakers and also into prom dresses.

Multipurpose Robot For The Masses

June 8, 2016 by Bryan Cockfield 13 Comments

As the cost of almost every technology comes falling down, from electronics to batteries to even tools like 3D printers, the cost to build things formerly out of reach of most of us becomes suddenly very affordable. At least, that’s what [John Choi] has found by building a completely DIY general purpose robot for around $2000.

OK, so $2000 isn’t exactly “cheap” but considering that something comparable (like Baxter) costs north of what a new car would cost means that [John] has dropped the price for a general-purpose robot by an order of magnitude. And this robot doesn’t skimp on features, either. It has a platform that allows it to navigate rooms, two manipulating limbs with plenty of servos, a laptop “head” that allows for easy interface, testing, and programming, and an Arduino Mega that allows it to interface with any sensors or other hardware with ease. It’s also modular so it can be repaired and transported easily, and it uses open source software and open hardware so it’s easy to build on.

This robot is an impressive piece of work that should help bring this technology to more than just high-end factories and research labs. They’ve already demonstrated the robot watering plants, playing the piano, picking things up, and many other tasks. We’d say that they’re well on their way to their goal of increasing the number of students and hobbyists who have access to this technology. If the $2k price tag is still too steep, though, there are other ways of getting into robotics without diving headfirst into a Baxter-like robot.

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Hand Gestures Play Tetris

May 28, 2016 by Bryan Cockfield 3 Comments

There are reports of a Tetris movie with a sizable budget, and with it come a plentiful amount of questions about how that would work. Who would the characters be? What kind of lines would there be to clear? Whatever the answers, we can all still play the classic game in the meantime. And, thanks to some of the engineering students at Cornell, we could play it without using a controller.

This hack comes from [Bruce Land]’s FPGA design course. The group’s game uses a video camera which outputs a standard NTSC signal and also does some filtering to detect the user. From there, the user can move their hands to different regions of the screen, which controls the movement of the Tetris pieces. This information is sent across GPIO to another FPGA which uses that to then play the game.

This game is done entirely in hardware, making it rather unique. All game dynamics including block generation, movement, and boundary conditions are set in hardware and all of the skin recognition is done in hardware as well. Be sure to check out the video of the students playing the game, and if you’re really into hand gesture-driven fun, you aren’t just limited to Tetris, you can also drive a car.

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Punch Cards

May 26, 2016 by Bryan Cockfield 41 Comments

Before the Commodore 64, the IBM PC, and even the Apple I, most computers took input data from a type of non-magnetic storage medium that is rarely used today: the punched card. These pieces of cardstock held programs, data, and pretty much everything used to run computers in the before-time. But with all of that paper floating around, how did a programmer or user keep up with everything? Enter the punch card sorter and [Ken Shirriff[‘s eloquent explanation of how these machines operate.

Card sorters work by reading information on the punched card and shuffling the cards into a series of stacks. As [Ken] explains, the cards can be run through the machine multiple times if they need to be sorted into more groups than the machine can manage during one run, using a radix sort algorithm.

The card reader that [Ken] examines in detail uses vacuum tubes and relays to handle the logical operation to handle memory and logic operations. This particular specimen is more than half a century old, rather robust, and a perfect piece for the Computer History Museum in Mountain View.

It’s always interesting to go back and examine (mostly) obsolete technology. There are often some things that get lost in the shuffle (so to speak). Even today, punched cards live on in the automation world, where it’s still an efficient way of programming various robots and other equipment. Another place that it lives on is in voting machines in jurisdictions where physical votes must be cast. Hanging chads, anyone?

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Star Trek Material Science Is Finally Real: Transparent Wood

May 19, 2016 by Bryan Cockfield 89 Comments

It’s not transparent aluminum, exactly, but it might be even better: transparent wood. Scientists at the University of Maryland have devised a way to remove all of its coloring, leaving behind an essentially clear piece of wood.

By boiling the block of wood in a NaOH and Na₂SO chemical bath for a few hours the wood loses its lignin, which is gives wood its color. The major caveat here is that the lignin also gives wood strength; the colorless cellulose structure that remains is itself very fragile. The solution is to impregnate the transparent wood with an epoxy using about three vacuum cycles, which results in a composite that is stronger than the original wood.

There are some really interesting applications for this material. It does exhibit some haze so it is not as optimally transparent as glass but in cases where light and not vision is the goal — like architectural glass block — this is a winner. Anything traditionally build out of wood for its mechanical properties will be able to add an alpha color channel to the available options.

The next step is finding a way to scale up the process. At this point the process has only been successful on samples up to 1 centimeter thick. If you’re looking to build a starship out of this stuff in the meantime, your best bet is still transparent aluminum. We do still wonder if there’s a way to eliminate the need for epoxy, too.

Self-Driving Cars Get Tiny

May 16, 2016 by Bryan Cockfield 4 Comments

There’s a car race going on right now, but it’s not on any sort of race track. There’s a number of companies vying to get their prototype on the road first. [Anurag] has already completed the task, however, except his car and road are functional models.

While his car isn’t quite as involved as the Google self driving car, and it doesn’t have to deal with pedestrians and other active obstacles, it does use a computer and various sensors to make decisions about how to drive. A Raspberry Pi 2 takes the wheel in this build, taking input from a Pi camera and an ultrasonic distance sensor. The Pi communicates to another computer over WiFi, where a neural network operates to make decisions about how to drive the car. It also makes decisions based on a database of pictures of the track, so it has a point of reference to go by.

The video of the car in action is worth a look. It’s not perfect, but it’s quite an accomplishment for this type of project. The possibility that self-driving car models could drive around model sets like model railroad hobbyists create is intriguing. Of course, this isn’t [Anurag]’s first lap around the block. He’s already been featured for building a car that can drive based on hand gestures. We’re looking forward to when he can collide with model busses.

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