Month: May 2016

Waste Not, No Lights

May 27, 2016 by 19 Comments

Alchemists tried in vain to transmute lead into gold. What if you could turn waste products into energy? That’s what [chemicum] did in a recent video–he and some friends built microbial fuel cells that convert excrement into electricity (you can see the video, below).

The video doesn’t give you all the details of the build, but it seems easy enough. You need some stainless steel mesh, some activated charcoal, some epoxy, plastic containers, and some assorted metal plates and hardware. Of course, you also need excrement and–if the video is any indication–some clothespins to clamp your nose shut as you work.

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Adventures Of ArduinoMan – The Rudis

May 27, 2016 by 50 Comments

Rudis – A small wooden sword given to a Gladiator as proof of his achieved freedom. It signifies his ascent from being a slave to becoming a free man.

One thing is certain – anything that runs on electricity can be connected to the internet. The only obstacle is cost. And as costs come down, the reality of The Internet of Things will be upon us. Everything from cars to curling irons will be connected to the Internet. With this newly connected world will come a new breed of hacker. The Black Hats will move out from behind their keyboards and spill into the streets, only to be met by the White Hats as they battle for control over our endlessly connected world.

And such was the case on the morning of October 16, 2029. The air was cool and breezy when Randall C. Tubbs, a senior police officer at the Bronx 49th precinct, received a call over his radio to check out a tripped alarm at a nearby cell tower. Barely a minute had passed by when he pulled in to the Tower Road cul-de-sac on the day our story begins. The cell tower dominated the horizon, and was silhouetted against a cloudless blue sky. The trees of the forest surrounding the area were just starting to show their colors, with the yellow oak leaves being most vibrant. A narrow gravel driveway led to a small, brown, nondescript building at the base of the tower. At first glance, Officer Tubbs could see no sign of anything unusual. There was no service truck in sight, and the gate to the ten-foot-tall chain link fence surrounding the tower was latched shut and securely locked.

It wasn’t until he unlocked the gate that he first noticed something odd. A security camera on the right corner of the building was pointing toward the forest. He glanced around and quickly spotted two other cameras, each of them pointing away from the tower building. Clearly, they should have been pointing toward the tower and the door to the building… a door that Officer Tubbs now realized was slightly open. He could barely make out shadows moving around from the small sliver of light that was peeking ominously through the opening, suggesting someone was inside. Suddenly, the sound of his footsteps on the gravel seemed to become amplified, and his breathing so loud that for a split second he held his breath. He reached down and turned the volume of his radio to silent, and slowly began making his way to the open door.

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DTMF Robot Makes Rube Goldberg Proud

May 27, 2016 by 11 Comments

Sometimes you start building, and the project evolves. Layers upon layers of functionality accrue, accrete, and otherwise just pile up. Or at least we’re guessing that’s what happened with [Varun Kumar]’s sweet “Surveillance Car Controlled by DTMF“.

In case you haven’t ever dug into not-so-ancient telephony, Dual-tone, multi-frequency signalling is what made old touch-tone phones work. DTMF, as you’d guess, encodes data in audio by playing two pitches at once. Eight tones are mapped to sixteen numbers by using a matrix that looks not coincidentally like the old phone keypad (but with an extra column). One pitch corresponds to a column, and one to a row. Figure out which tones are playing, and you’ve decoded the signal.

Anyway, you can get DTMF decoder chips for pennies on eBay, and they make a great remote-control interface for a simple robot, which is presumably how [Varun] got started. And then he decided that he needed a cell phone on the robot to send back video over WiFi, and realized that he could also use the phone as a remote controller. So he downloaded a DTMF-tone-generator app to the phone, which he then controls over VNC. Details on GitHub.

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Retrotechtacular: Examining Music In 1950’s Russia

May 27, 2016 by 34 Comments

If you had told 12-year-old me that one day I would be able to listen to pretty much any song I wanted to on demand and also pull up the lyrics as fast as I could type the artist’s name and part of the title into a text box, I would have a) really hoped you weren’t kidding and b) would have wanted to grow up even faster than I already did.

The availability of music today, especially in any place with first world Internet access is really kind of astounding. While the technology to make this possible has come about only recently, the freedom of music listening has been fairly wide open in the US. The closest we’ve come to governmental censorship is the parental advisory sticker, and those are just warnings. The only thing that really stands between kids’ ears and the music they want to listen to is parental awareness and/or consent.

However, the landscape of musical freedom and discovery has been quite different in other corners of the world, especially during the early years of rock ‘n roll. While American teens roller skated and sock-hopped to the new and feverish sounds of Little Richard and Elvis Presley, the kids in Soviet Russia were stuck in a kind of sonic isolation. Stalin’s government had a choke hold on the influx of culture and greatly restricted the music that went out over the airwaves. They viewed Western and other music as a threat, and considered the musicians to be enemies of the USSR.

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Hackaday Prize Entry: Open-Source Myoelectric Hand Prosthesis

May 26, 2016 by 9 Comments

Hands can grab things, build things, communicate, and we control them intuitively with nothing more than a thought. To those who miss a hand, a prosthesis can be a life-changing tool for carrying out daily tasks. We are delighted to see that [Alvaro Villoslada] joined the Hackaday Prize with his contribution to advanced prosthesis technology: Dextra, the open-source myoelectric hand prosthesis.

dextra_handDextra is an advanced robotic hand, with 4 independently actuated fingers and a thumb with an additional degree of freedom. Because Dextra is designed as a self-contained unit, all actuators had to be embedded into the hand. [Alvaro] achieved the necessary level of miniaturization with five tiny winches, driven by micro gear motors. Each of them pulls a tendon that actuates the corresponding finger. Magnetic encoders on the motor shafts provide position feedback to a Teensy 3.1, which orchestrates all the fingers. The rotational axis of the thumb is actuated by a small RC servo.

mumai_boardIn addition to the robotic hand, [Alvaro] is developing his own electromyographic (EMG) interface, the Mumai, which allows a user to control a robotic prosthesis through tiny muscle contractions in the residual limb. Just like Dextra, Mumai is open-source. It consists of a pair of skin electrodes and an acquisition board. The electrodes are attached to the muscle, and the acquisition board translates the electrical activity of the muscle into an analog voltage. This raw EMG signal is then sampled and analyzed by a microcontroller, such as the ESP8266. The microcontroller then determines the intent of the user based on pattern recognition. Eventually this control data is used to control a robotic prosthesis, such as the Dextra. The current progress of both projects is impressive. You can check out a video of Dextra below.

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Nanowire Batteries Never Need Replacing

May 26, 2016 by 47 Comments

In this day and age we’re consistently surrounded with portable electronic devices. In order for them to be called “portable”, they must run on batteries. Most, if not all, use rechargeable batteries. These batteries have a finite lifespan, and will eventually need to be replaced. UCI chemist [Reginald Penner] and doctoral candidate [Mya Le Thai] have been hard at work on making rechargeable batteries that last forever.

Nanowires are great candidates for rechargeable battery technology because the wires, thousands of times thinner than a human hair, are great conductors of electricity. The problem is repeated charging and discharging makes them brittle, which causes them to eventually fail. Typically, the researchers at UCI could get 5000 to 7000 cycles in before they failed. After some trial and error, they found that if they coat a gold nanowire with an acrylic-like gel, they can get up to 200,000 charge/discharge cycles through it before failure.

We’ve seen rechargeable battery hacks before, but making a battery that never needs replacing is sure to get everyone excited.

Punch Cards

May 26, 2016 by 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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