8 Bit Message In A Digital Bottle

December 7, 2014 by Sarah Petkus 20 Comments

As seasoned data-travelers, we’re used to wielding the internet to send messages and communicate to others without any limitations. No one has to be stranded on a figurative island blowing smoke signals… unless of course they wanted to be. What [Harm Alexander Aldick] has done with his project “Lorem Ipsum”, is create a situation where others can only communicate to him through a sort of message in a bottle. The bottle in this case is an electronic widget.

In this social experiment, [Harm] has stationed a small Ikea picture frame at his desk, which shows images and text sent to him in real-time from others in the world. With an Arduino as the brain, a small 8×8 LED matrix mounted at the bottom right of the frame displays the data received by means of an ethernet module. Anyone can use his web interface to modify the pixels of the matrix on a virtual version of the installation. Once sent, the message is transmitted through an IPv6 internet connection and is translated to UDP which the unit is controlled by.

[Harm]’s project investigates how people react when given the chance to send a message in complete anonymity to someone they don’t know… in of all things, the form of something as limited as 64 pixels. The project name “Lorem Ipsum” refers to the filler text used in graphic design to hold the place of what would otherwise be more meaningful information, so that it doesn’t detract from the experience of viewing the layout. Curious about what sort of ‘graphical experience’ I would come up with myself, I took a shot at punching away at [Harm’s] GUI. I got momentarily lost in turning the little red dots on and off and eventually turned out this little ditty:

It was supposed to be something of a triangle, yet turned into a crop circle… or pronged nipple. After it was sent, I wondered whether or not [Harm] actually saw it. In the case that he did, I can only imagine what I communicated to our fellow hacker abroad with my squall of dots. All of these thoughts though are the whole point of the project. Awesome work!

An Expanding Wooden Table

December 7, 2014 by Brian Benchoff 28 Comments

A few years ago, the world of fine woodworking was presented with the Fletcher Capstan table. It’s a round table, able to expand its diameter merely by rotating the top. A gloriously engineered bit of mechanics move the leaves of the tables out while simultaneously raising the inner part of the table. It’s a seriously cool table, very expensive, and something that will probably be found in museums 100 years from now.

[Scott Rumschlag] thought his woodworking skills were up to the task of creating one of these expanding tables and managed to build one in his workshop. Like the Fletcher Capstan table, it’s a table that increases its diameter simply by rotating the table top. Unlike the commercial offering, this one doesn’t cost as much as a car, and you can actually see the internal mechanism inside this table.

The top of [Scott]’s table is made of three pieces. The quarter-circle pieces are the only thing showing when the table is in its minimum position, and are arranged on the top of the ‘leaf stack’. When the table expands, four additional leaves move up from beneath with the help of a linear bearing made of wood and a roller that slides along the base of this mechanical contraption.

The center of the table – the star – is a bit more difficult to design. While the leaves move up the stack of table tops with the help of a ramp, this is an impractical solution for something so close to the center of the table. Instead of a ramp, [Scott] is using a lifting lever and metal hinge that brings the star of the table up to the right level. Even though it’s a crazy amount of woodworking and fine tuning to get everything right, it’s not too terribly difficult to get your head around.

Videos, including one of the assembly of the table, below.

Continue reading “An Expanding Wooden Table” →

Schematic for a boost converter based on the ATtiny MCU

An ATtiny Boost Converter

December 7, 2014 by Eric Evenchick 49 Comments

This schematic is all you need to build your own voltage converter. [Lutz] needed a converter that could boost 5 V to 30 V to power a string of LEDs. The solution was to use low cost ATtiny85 and some passive components to implement a boost converter.

This circuit follows the classic boost converter topology, using the ATtiny85 to control the switch. The 10 ohm resistor is fed back into the microcontroller’s ADC input, allowing it to sense the output voltage. By measuring the output voltage and adjusting the duty cycle accordingly, the circuit can regulate to a specified voltage setpoint.

A potentiometer is used to change the brightness of the LEDs. The software reads the potentiometer’s output voltage and adjusts the voltage output of the circuit accordingly. Higher voltages result in brighter LEDs.

Of course, there’s many other ways to implement a boost converter. Most practical designs will use a chip designed for this specific purpose. However, if you’re interested in rolling your own, the source and LTSpice simulation files are available.

Amazon Fire TV Update Bricks Hacked Devices

December 7, 2014 by Rick Osgood 60 Comments

The Amazon Fire TV is Amazon’s answer to all of the other streaming media devices on the market today. Amazon is reportedly selling these devices at cost, making very little off of the hardware sales. Instead, they are relying on the fact that most users will rent or purchase digital content on these boxes, and they can make more money in the long run this way. In fact, the device does not allow users to download content directly from the Google Play store, or even play media via USB disk. This makes it more likely that you will purchase content though Amazon’s own channels.

We’re hackers. We like to make things do what they were never intended to do. We like to add functionality. We want to customize, upgrade, and break our devices. It’s fun for us. It’s no surprise that hackers have been jail breaking these devices to see what else they are capable of. A side effect of these hacks is that content can be downloaded directly from Google Play. USB playback can also be enabled. This makes the device more useful to the consumer, but obviously is not in line with Amazon’s business strategy.

Amazon’s response to these hacks was to release a firmware update that will brick the device if it discovers that it has been rooted. It also will not allow a hacker to downgrade the firmware to an older version, since this would of course remove the root detection features.

This probably doesn’t come as a surprise to most of us. We’ve seen this type of thing for years with mobile phones. The iPhone has been locked to the Apple Store since the first generation, but the first iPhone was jailbroken just days after its initial release. Then there was the PlayStation 3 “downgrade” fiasco that resulted in hacks to restore the functionality. It seems that hackers and corporations are forever destined to disagree on who actually owns the hardware and what ownership really means. We’re locked in an epic game of cat and mouse, but usually the hackers seem to triumph in the end.

Raspberry PiPhone Thermostat Monitors Your Entire House — Or At Least That’s The Plan

December 6, 2014 by James Hobson 18 Comments

[Jeff McGehee] or how he likes to be known, [The Nooganeer] just finished his first big tech project after finishing grad school. It’s a connected thermostat that makes use of his old iPhone 4, and a Raspberry Pi.

Ever since [The Nooganeer] bought his first home with his wife back in the spring of 2014, he’s had ever consuming dream of adding home automation to every appliance. As he puts it…

Home automation has always been a fascination of mine. How much time and irritation would I save if I didn’t have to worry about turning things on and off, or wonder in which state they were left? How much more efficient would my home be? Wouldn’t it be cool to always know the state of every power consumer in my home, and then be able to record and analyze that data as well?

His first challenge was making a smart thermostat — after all, heating and cooling your house typically takes the most energy. Having used a Raspberry Pi before he figured it would be the best brain for his system. After researching a bit about HVAC wiring, [The Nooganeer] settled on a Makeatronics Solid State Relay board to control the HVAC. This allows him to use the GPIO’s on the Raspberry Pi in order to control the furnace and AC unit. Continue reading “Raspberry PiPhone Thermostat Monitors Your Entire House — Or At Least That’s The Plan” →

Scanning On The Cheap

December 6, 2014 by Brian Benchoff 20 Comments

[Will] recently stumbled across the MakerBot Digitizer, a device that’s basically a webcam and a turntable that will turn a small object into a point cloud that can then be printed off on a MakerBotⓇ 3D printer. Or any other 3D printer, for that matter. The MakerBot Digitizer costs $800, and [Will] wondered if he could construct a cheaper 3D scanner with stuff sitting around his house. It turns out, he can get pretty close using only a computer, a webcam, and a Black and Decker line laser/level.

The build started off with a webcam mounted right next to the laser line level. Software consisted of Python using OpenCV, numpy, and matplotlib to grab images from the webcam. The software looks at each frame of video for the path of the laser shining against the object to be scanned. This line is then extracted into a 3D point cloud and reconstructed in MeshLab to produce a 3D object that might or might not be 3D printable.

This is only [Will]’s first attempt at creating a scanner. He’s not even using a turntable with this project – merely manually rotating the object one degree for 360 individual frames. It’s extremely tedious, and he’ll be working on incorporating a stepper motor in a future version.

This is only attempt number 1, but already [Will] has a passable scanned object created from a real-world thing.

Cordless Drill Turned Into Bicycle-Powered Generator

December 6, 2014 by Rich Bremer 27 Comments

The bicycle is a great invention. It is an extremely efficient method of transportation, even more so than walking. So why not harness that efficiency for other things? [Tony] had that same thought so he ordered a bike generator but after waiting too long for the company to send it, he decided to make his own.

[Tony] is an bicycle enthusiast so he had an old bike and an old training stand he could use for the project. Generating electricity from pedaling the bike requires some sort of generator. Lucky for him, [Tony] happened to have a cordless drill that stopped going in reverse. Since he had since upgraded, this was the perfect candidate for the generator. The drill was mounted to the training stand so that a pulley inserted in the chuck pressed against the rear wheel. Wires were added to connect the drill’s battery connectors to a 12vdc to 120vac inverter. As the bike is pedaled, the rear wheel spins the drill, which spins the drill motor creating DC voltage. That DC voltage is then converted to AC by the inverter. With a multimeter connected to the output from the drill, it is easy to adjust the pedaling speed to keep the output in the 11-14v range which is required by the inverter.

In the photo above, you can see a light bulb being powered by the bike. However, the bike powered generator could not power the larger load of a computer. The remedy for this was to purchase a solar charge controller and a 12 volt battery. The bike charges the battery and the battery can power the computer through the inverter.