Interactive Dynamic Video

August 26, 2016 by Adam Fabio 12 Comments

If a picture is worth a thousand words, a video must be worth millions. However, computers still aren’t very good at analyzing video. Machine vision software like OpenCV can do certain tasks like facial recognition quite well. But current software isn’t good at determining the physical nature of the objects being filmed. [Abe Davis, Justin G. Chen, and Fredo Durand] are members of the MIT Computer Science and Artificial Intelligence Laboratory. They’re working toward a method of determining the structure of an object based upon the object’s motion in a video.

The technique relies on vibrations which can be captured by a typical 30 or 60 Frames Per Second (fps) camera. Here’s how it works: A locked down camera is used to image an object. The object is moved due to wind, or someone banging on it, or any other mechanical means. This movement is captured on video. The team’s software then analyzes the video to see exactly where the object moved, and how much it moved. Complex objects can have many vibration modes. The wire frame figure used in the video is a great example. The hands of the figure will vibrate more than the figure’s feet. The software uses this information to construct a rudimentary model of the object being filmed. It then allows the user to interact with the object by clicking and dragging with a mouse. Dragging the hands will produce more movement than dragging the feet.

The results aren’t perfect – they remind us of computer animated objects from just a few years ago. However, this is very promising. These aren’t textured wire frames created in 3D modeling software. The models and skeletons were created automatically using software analysis. The team’s research paper (PDF link) contains all the details of their research. Check it out, and check out the video after the break.

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Books You Should Read: The Soul Of A New Machine

August 26, 2016 by Adam Fabio 47 Comments

If there was one book that describes what it means to be in the trenches of a cutting edge design, that book is The Soul Of a New Machine. Tracy Kidder’s Pulitzer prize-winning book has been an inspiration to thousands over the years.

Soul is the story of the creation of the Data General Eclipse MV/8000, code-named Eagle. Eagle was Data General’s first 32-bit minicomputer. If you’re not a retrocomputing aficionado, minicomputers were a major industry back in the 70’s and 80’s. Starting in 1964 with the Digital Equipment Corporation (DEC) PDP-8, minis provided a low-cost means for companies to get a computer. The only other option was a huge mainframe from companies like IBM. Minicomputers chugged along until the 1990s when microprocessor-based PCs and workstations passed them by. The market, and the industry evaporated.

Today, more than 30 years later, minicomputers are all but forgotten. Data General itself is long gone, purchased by EMC in 1999. DG’s mark on the landscape has all but been erased by the swiftly moving sands of technical progress. All except for the snapshot Kidder set down in Soul.

An MV/8000 installation (from DG literature)

The technical side of designing a new computer is just one part of this book. The Soul of a New Machine is three stories: the story of the engineers, the story of the managers, and the story of the machine they built. For this reason, the book has found itself on the reading list of engineering schools and management institutes alike.

The thing that makes this book appeal to the masses is Kidder’s uncanny ability to explain incredibly complex topics in layman’s terms. He manages to explain the inner workings of a 32-bit CPU, all the way down to the level of microcode. He delves into Programmable Array Logic (PALs), forerunners of the CPLD and FPGA devices you read about on our pages today. PALs were a hot new technology back in the late 70’s. They allowed the Eagle team to make changes quickly — without pulling out their wire wrapping tools.

Kidder manages to explain these things in a way that doesn’t leave the average Joe scratching their head, yet doesn’t bore the technically savvy. If he ever decides to stop writing non-fiction, Tracy Kidder would have a career writing user manuals.

The Soul of a New Machine starts in a very unlikely place – on the deck of a sailing ship during a rough storm. The scene is our introduction to the star of the book – Tom West, a manager at Data General. West is multifaceted and enigmatic to say the least. A folk guitarist who was inspired to work on electronics by the Apollo program. He was a few years too late for NASA though. Eventually he found himself travelling the world building and adjusting incredibly accurate clocks at astronomical observatories for the Smithsonian. This meandering path eventually led him to DG, where he was hired as a computer engineer and quickly worked his way up the ranks.

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A Refrigerator Cooled By Rubber Bands

August 25, 2016 by Adam Fabio 35 Comments

Ever noticed that a rubber band gets warmer when it’s stretched? The bands also get cooler when allowed to snap back to relaxed length? [Ben Krasnow] noticed, and he built a rubber band cooled refrigerator to demonstrate the concept. The idea of stretching a rubber band to make it hotter, then releasing it to make it cooler seems a bit counter intuitive. Normally when things get smaller (like a gas being compressed) they get hotter. When pressure is released the gas gets cooler. Rubber bands do the exact opposite. Stretching a rubber band makes it hot. Releasing the stretched band causes it to get cooler.

No, the second law of thermodynamics isn’t in jeopardy. The secret is in the molecular structure of rubber bands. The bands are made of long polymer chains. A relaxed rubber band’s chains are a tangled mess. Stretching the band causes the chains to untangle and line up in an orderly fashion. By stretching the band you are decreasing its entropy. The energy of the molecules in the band don’t change, but entropy does. All the work one does to stretch the band has to go somewhere, and that somewhere is heat. This is all an example of entropic force. For a physics model of what’s going on, check out ideal chains. If you’re confused, watch the video. [Ben] does a better job of explaining entropic force visually than we can with text.

To test this phenomenon out, [Ben] first built a wheel with rubber bands as spokes. Placing the wheel in front of a heater caused it to slowly rotate. [Ben] then reversed the process by building a refrigerator. He modeled his parts in solidworks, then cut parts with his Shaper handheld CNC. The fridge itself consists of an offset wheel of rubber bands. The bands are stretched outside the fridge, and released inside. Two fans help transfer the thermal energy from the bands to the air. The whole thing is hand cranked, so this would make a perfect museum or educational demonstration. Cranking the fridge for 5 minutes did get the air inside a couple of degrees cooler. Rubber is never going to displace standard refrigerants, but this is a great demo of the principles of entropic force.

For more thermodynamic fun, check out [Al Williams] recent article about building a DIY heat pipe.

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Roomba Vs Poop: Teaching Robots To Detect Pet Mess

August 24, 2016 by Adam Fabio 119 Comments

Imagine this: you come home after a day at work. As you open the door, your nose is the first alert that something is very, very wrong. Instead of the usual house smell, your nose is assaulted with the distinctive aroma that means your dog had an accident. The smell is stronger though — as if Fido brought over a few friends and they all had a party. Flipping the lights on, the true horror is revealed to you. This was a team effort, but only one dog was involved.

At some point after the dog’s deed, Roomba, your robot vacuum, took off on its scheduled daily run around the house. The plucky little robot performed its assigned duties until it found the mess. The cleaning robot then became an agent of destruction, smearing a foul smelling mess throughout the space it was assigned to clean. Technology sometimes has unintended consequences. This time, your technology has turned against you.

This scene isn’t a work of fiction. For a select few families, it has become an all too odoriferous reality just begging for a clever fix.

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D.Va For Real: Playing An FPS With Flight Sticks

August 20, 2016 by Adam Fabio 18 Comments

[Rudeism] loves playing Blizzard’s hit game Overwatch. He wanted to make his gaming experience a bit more realistic though. One of the characters is D.Va, who according to game lore is a member of the South Korean Mobile Exo-Force (MEKA). D.Va pilots her MEKA in game using two joysticks. Overwatch is a standard FPS with WASD and mouse controls, so the realism ends at the screen.

[Rudeism] didn’t let that stop him. He used two flight sticks to create the ultimate D.Va experience. [Twitch recording link – language warning] A commercial software package called Xpadder allowed him to map movements on the joystick to mouse and keystrokes. The left joystick maps to WASD, left shift, Q, and right click. The right stick corresponds to mouse movements, E, and left click.

This isn’t exactly the tank style steering we’re used to from classic mech games like Virtual-On, but it’s pretty good for a software solution. It makes us wonder what would be possible with a bit of hardware hacking – perhaps a Teensy handling the analog and button inputs.

People have been coming up with interesting ways to play video games for years. Check out this hack with the classic Microsoft Kinect, or these arcade hacks.

Via Reddit

Hacklet 121 – Tea Hacks

August 20, 2016 by Adam Fabio 19 Comments

Last week on the Hacklet I covered coffee hacks. Not everyone likes coffee though. A good portion of the world’s population enjoys a nice cup of tea. Different cultures are rather particular with how they prepare their drink of choice. Americans tend to use teabags, while British, Chinese (and much of the rest of the globe) generally prefer loose tea leaves. Everyone has their own particular style, which has led to quite a few tea hacks. This week’s Hacklet is all about some of the best tea projects on Hackaday.io!

We start with [James P.] and Tea Pi. Tea Pi is designed to emulate commercial tea makers costing hundreds of dollars. The heart of the operation is a Raspberry Pi, making this one of the first Linux powered tea makers we’ve ever heard of. An Adafruit PowerSwitch Tail allows the Pi to control a standard tea kettle. The Pi monitors water temperature with a DS18B20 temperature sensor. A simple servo drops a tea basket into the water for brewing. When the time is up, the servo pulls the basket up and the tea is ready to serve. [James P] planned to add voice control to his tea creation. I’m betting that would be pretty easy with Amazon’s voice services for the Raspberry Pi.

Next up is [Tom] with Eye-O-Tea. With this project, even your cup of tea can join the Internet of Things. Eye-O-Tea essentially is a web connected coaster with temperature monitoring built right in. Temperature is measured with a Melexis MLX90615 IR thermometer. An Arduino Pro Mini reads the temperature and passes it on to an ESP8266 WiFi module. The entire device is powered by a LiPo battery, and neatly housed in a gutted cup warmer. On the cloud side, [Tom] used ThinkSpeak and freeboard.io to make an interface he can access with his cell phone. If his tea is too hot, Eye-O-Tea will let him know. It will also send him an SMS if he’s forgotten his cup and it’s going cold.

Next we have [Adrian] and ChaiBot. Chaibot was created by [Adrian’s] son [Oliver] to combat a common problem. Both father and son would pour cups of tea, then get involved in a project. By the time they came back, they had ink. ChaiBot steeps the tea for a set amount of time, stirring every minute. The mechanics of the project came from an old CD-ROM drive. A PIC16F887 runs the show, ensuring the steep time is accurate, and activating the motor drive. When the tea is done, an ESP8266 sends a push notification to the user’s phone. The project is housed in a wooden case that fits perfectly on the kitchen counter.

Finally, we have [Siggi] with Camper Induction Cooker, a 2016 Hackaday Prize entry. [Siggi] needed hot liquids on the go, but he didn’t want to fool around with heating elements. An induction heater was the way to go. A Cypress PSOC micro controls the system. Metal travel style mugs can be used without modification. For ceramic or plastic mugs, a metal washer (hopefully coated with something food safe) acts as an immersion heater. The project is definitely a bit unwieldy at the moment, but I could see [Siggi’s] idea being incorporated into automotive cup holders. [Siggi] put his project on hold back in June. I hope seeing his work on the front page will get development moving again.

If you want to see more tea projects, check out our new tea projects list. See a project I might have missed? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Skin Bling: Wearable Electronics From Golden Temporary Tattoos

August 16, 2016 by Adam Fabio 21 Comments

MIT Media Lab and Microsoft have teamed up to take wearable devices one step further — they’ve glued the devices directly to the user’s skin. DuoSkin is a temporary tattoo created with gold leaf. Metallic “Flash” temporary fashion tattoos have become quite popular recently, so this builds on the trend. What the team has done is to use them to create user interfaces for wearable electronic devices.

Generally speaking, gold leaf is incredibly fragile. In this process to yield the cleanest looking leaf the gold is not actually cut. Instead, the temporary tattoo film and backer are cut on a standard desktop vinyl cutter. The gold leaf is then applied to the entire film surface. The cut film/leaf can then be “weeded” — removing the unwanted portions of film which were isolated from the rest by the cutting process — to complete the temporary tattoo. The team tested this method and found that traces 4.5 mm or more thick were resilient enough to last the entire day on your skin.

The gold leaf tattoos make excellent capacitive touch sensors. The team was able to create sliders, buttons, and even 2 dimensional diamond grids. These controls were used to move a cursor on a computer or phone screen. They were even able to create a wearable NFC tag. The gold leaf is the antenna, and the NFC chip itself is mounted on the temporary tattoo backer.

These devices all look great, but with the exception of the NFC chip, we’re not seeing the electronics driving them. Capacitive touch sensors used as a UI for a phone will have to have a Bluetooth radio and a battery somewhere. We’re that’s all hidden under the arm of the user. You can see what we’re taking about in the video after the break. That said, the tools and materials are ubiquitous and easy to work with. Take a quick read through the white paper (PDF) and you can be making your own version of this today.

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