Trick Google Used Hides Secret Messages On LCD Screens

July 15, 2015 by Adam Fabio 37 Comments

[Travis] didn’t get picked to go to Google I/O this year, but he did have some I/O inspired fun after the fact. His friends who did go told him about specially modified LCD screens Google had scattered around the event. The screens showed normal show information when viewed with the naked eye. When viewed through a special transparent badge included with the I/O swag though, a URL for Google’s scavenger hunt would magically appear. [Travis] was intrigued by the effect, and became hell-bent on reproducing it himself.

[Travis] figured out the transparent badge was actually a polarizing filter. Every standard LCD has two of them, usually bonded to the glass of the LCD itself. If you remove the filters from a LCD, you’ll get a prime view of the backlight – unless you’re wearing polarizing glasses of course. Google’s monitors didn’t have that effect though. They showed a full color display, with a second full color hidden display only visible through the polarizer. [Travis] is intelligent and experienced, so it only took a bit of three-dimensional thinking for him to figure out Google’s trick. There are actually two LCDs used in the display. The first is a standard LCD with backlight. The trick is to strip the polarizing film off a second LCD and place it in front of the first. The second LCD will be invisible to anyone – without the polarizer.

[Travis] quickly set about replicating the display using several obsolete VGA LCDs. He quickly found that the hard part was peeling the polarizing plastic from the thin glass LCD sandwich. Several LCDs gave up their lives in the effort, but in the end [Travis] was successful. He made everything fit in one case by using a thin LED backlight in a case designed for a monitor with a Cold Cathode Fluorescent Lamp (CCFL). The result looks exactly like a standard LCD – that is, until viewed through a polarizing filter. Click past the break to see the hidden message LCD in action!

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Hacklet 55 – Home Automation Projects

July 10, 2015 by Adam Fabio 16 Comments

Home automation – the idea of a smart home that monitors and controls the inside environment, takes commands from occupants, and generally makes living easier. Hackers, makers, and engineers have been building their own vision of the smart home for decades. Thanks to cell phones and the revolution of the “internet of things”, home automation is now in the public eye. The hackers haven’t stopped though. They’re still building dreams, one circuit and one line of code at a time. This week’s Hacklet is dedicated to some of the best home automation projects on Hackaday.io!

We start at the top – [IamTeknik’s] Project Jarvis has been in the top five skulled and viewed projects on Hackaday.io for as long as we’ve been keeping records. Just like the fictional Tony Stark design which inspired its name, Jarvis is based on artificial intelligence. [IamTeknik] has created a system using the BeagleBone Black running his own custom software. He’s also creating Jarvis from the ground up – even the relay modules have been designed and built by [IamTeknik]. So far Jarvis has a great 3D printed door lock unit, and a really nice wall mounted tablet. We’re watching to see what modules [IamTeknik] adds next!

[Morrisonpiano] is no home automation noob. He’s been running his own system for two decades. HCS_IV Home Automation System is a project to update his HCS_C home automation system. For the uninitiated, the original HCS was created by [Steve Ciarcia] of Byte and Circuit Cellar fame. There have been several generations of the hardware and software since then, with plenty hackers adding their own custom features. [Morrisonpiano] is updating his system with an NXP Arm Cortex M4 CPU, three big Altera Cyclone FPGAs, and plenty of flash storage. Why use a FPGA on a home automation system? I/O of course! HCS uses a ton of I/O. There are 16 RS485 ports and 10 RS232 serial ports. Going with an FPGA makes things flexible as well. Want to add CAN bus? Just drop in some CAN HDL code and you’re golden!

[Steven] is giving the smart home more senses with Squirco Smart Home System – Sensor Network. Rather than just have a temperature sensor at the thermostat, or a motion detector in the front foyer, [Steven] wants a network of unobtrusive sensors to blanket the home. He’s doing this by replacing the common light switch with a smart module that has sensors for temperature, humidity, and human presence. [Steven] has spent quite a bit of time researching and experimenting microwave tomography as a means to detect humans. Going with microwaves means no obvious PIR windows.

Finally, we have [Ansaf Ahmad] with BeagleBone Black Home Automation. The idea for this project came from a calculus class on optimization. [Ansaf] is putting mathematical theorems to use in the real world by monitoring usage patterns and current demands of a device. With that data, he can optimize the usage to make things greener. So far, [Ansaf] has been experimenting with a lamp. The system has a web front end which uses PHP. The GPIO pins on the board are controlled using Python and Flask. As an early project, BeagleBone Home Automation is doing great – it’s already earned [Ansaf] high grades in his computer engineering class!

If you want more smart home goodness, check out our updated home automation projects list! Did I miss your project? 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!

CAPTION CERN CONTEST – Saying Goodbye To An Old Friend

July 9, 2015 by Adam Fabio 4 Comments

The tangled web woven by Week 22 of the Caption CERN Contest has come to a close. It’s been another bumper week with 112 comments. Thank you to everyone who submitted a caption! We realize it may have been hard for some of the network engineers out there to type through their tears, but thank you for persevering! While we don’t know exactly what these two CERN scientists were wiring up, [rwells97] did figure out that the scope in the image is most likely a Tektronix 545/A, which was a popular scope back in the late 1950s and early 1960s. The weight on a beast like that was around 70 lbs!

The Funnies:

“Dude, this one’s full of wires too! Every single one of these is full of wires! Why would anyone need so many wires? What in the name of God were they DOING down here?” – [The Green Gentleman]
“Getting to blinky” required a whole lot more work then the engineers realized…” – [Kieran Paulger]
“I think I lost an electron back here, Bob. I’m positive.” – [Christine Hampton]

This week’s winner is [alan] with “Daft Punk was actually two of CERN’s best acoustics researchers prior to forming the band. Here they are after hours working on the track that would later be named ‘Da Funk'”. [Alan] is a Computer Science PhD candidate with focus on computational biology, specifically population genomics. Hopefully he has some hardware in the mix somewhere, because we’re sending him a Stickvise from The Hackaday Store!

Week 23

Something a bit different this week. CERN is probably best known for the various particle accelerators they’ve had over the years. One of the first units was synchrocyclotron SC-1, which operated from 1957 to 1974. According to the album page on CERN’s servers, SC-1’s last day of operation was celebrated with a funeral procession. Scientists, and staff walked the grounds with flowers, top hats, and even a shrouded coffin. We can all related to decommissioning a well-worn piece of equipment. Be it a computer, a machine tool, or even a synchrocyclotron, there are always the mixed feelings of thanks that it did a good job, and relief that it will no longer need to be maintained.

Even though we have a pretty good idea of what’s going on in this image, we’re going to caption it anyway! Give us your best captions of what you think is really going on here! This week’s prize is a LightBlue Bean from The Hackaday Store. Add your humorous caption as a comment to this project log. Make sure you’re commenting on the contest log, not on the this post. As always, if you actually have information about the image or the people in it, let CERN know on the original image discussion page.

Headphone Amp Features A Tiny CRT

July 7, 2015 by Adam Fabio 40 Comments

[ErikaFluff] needed an amp for her Grado open cans. Rather than build yet another boring black box, she built what may be the most awesome headphone amp ever by adding a tiny CRT which displays the current audio waveform. She packaged all this up in a customized Hammond box which makes it look like it just rolled off the line from some audiophile studio.

The amplifier in this case is based upon the CMoy, a common headphone amp design. [ErikaFluff] added a MOSFET on the output to drive his relatively low impedance (32 ohm) Grado headphones with reasonable volume. The CRT is from an old video camera viewfinder. Before LCDs were advanced and cheap enough to include in video cameras, CRTs were the only show in town. These tiny black and white screens use high voltage to scan an electron beam across a phosphor screen just like their bigger brethren.

Since she was going with an oscilloscope style vector scan rather than the raster scan the screen electronics were originally designed for, [ErikaFluff] had to create her own horizontal and vertical deflection circuits. Horizontal scan is created by a 555 timer generating a sawtooth wave at 75 Hz. Vertical deflection is via an LM386 driving a hand wound impedance matching transformer. The high voltage flyback transformer and its associated driver circuit were kept from the original CRT, though repackaged to make them as small as possible.

You might think that having a few thousand volts next to a sensitive audio amplifier would cause some noise issues. We also worried a bit about shorts causing unexpected shock treatments through the wearer’s ears. [ErikaFluff] says there is no need to for concern — the signal is fed to the CRT circuit through optocouplers. The audio circuit is also electrically split from the CRT and runs on a virtual ground. Judicious amounts of shielding tape keeps the two circuits isolated.

This may not be the most practical project, but we think it’s pretty darn cool. The response over on Reddit’s electronics subreddit seems to be positive as well. We hope [ErikaFluff] is sitting down when this post gets published!

Caption CERN Contest – Cut The Black Wire

July 4, 2015 by Adam Fabio 13 Comments

Week 21 of the Caption CERN Contest is now history. It’s been a great week of captions, so as always a huge thank you goes out to everyone who entered. We still have no idea what these two CERN scientists were working on. Lenses, switches, and a giant glass screen which could have anything behind it. It’s a tough one. But what we lack in facts, you all made up for in humor.

The Funnies:

“I spy with my quantum eye, something with a 75% probability of being spin up!”- [bbarrett90]
“Preping the Voight-Kampff set up, they have learnt from their unfortunately predecessors that a mirrored bullet proof glass between them and the upset replicant subject might be a good idea.” -[K.C. Lee]
“Mary and Steve swore that they were going to be the ones to win this year’s where’s Waldo competition, unfortunately they lost to the guys in the next lab with an SEM.” – [TrollinTeemo]

This week’s winner is [Lou] with “CERNs early attempts at a retina scanner were a bit cumbersome and time consuming. You had to get to work 20 minutes early just to get past the security check.” Lou’s bio is “Test engineer with Mechanical background who likes to tear things apart”. We bet he’s going to enjoy using his new Teensy 3.1 from The Hackaday Store to build something new with all the parts he has left over from teardowns!

Week 22

Holy cable gore, Batman! This image may make a network engineer or IT person weep, but it was business as usual back in the early days of CERN. 14 racks of equipment, with coaxial cables running everywhere. Let’s hope all those patches are connected to the correct ports! What were these two CERN scientists working on? It’s up to you to tell us as CERN has lost the records!

While you’re working on your captions, check out the old oscilloscope the standing scientist is using. Scope carts used to be necessary. Today all but the most powerful oscilloscopes weigh in at under 10 pounds.

This week’s prize is a Stickvise from The Hackaday Store. Add your humorous caption as a comment to this project log. Make sure you’re commenting on the contest log, not on the contest itself. As always, if you actually have information about the image or the people in it, let CERN know on the original image discussion page.

Good Luck!

Hacklet 54 – Virtual Reality Projects

July 3, 2015 by Adam Fabio 4 Comments

Virtual Reality is finally coming of age. Hackers, Makers and Engineers have dreamed of creating immersive interfaces for years. From the first flight simulators to today’s cellphone powered head mounted displays, VR has always been an exciting field. Many of the advances today are being created by hackers who were inspired by systems like Virtuality from the early 1990’s. Now 25 years on, we’re seeing amazing advances – not only in commercial systems, but in open source VR projects. This week’s Hacklet is all about the best VR projects on Hackaday.io!

We start with [j0nno] and D.I.Y Virtual Reality. [J0nno] has become interested in VR, and decided to build his own head mounted display. His goal is to create a setup with full head tracking and an open source software stack. He’s hoping to do this within a budget of just $200 AUD. [J0nno] started with the Ritech3d-V2 VR Goggles, which are a plastic implementation of Google’s project cardboard. For display he’s using a 5.6 inch 1280 x 800 TFT LCD. Tracking is optical, using IR LEDs and a PS3 Eye camera. [J0nno’s] background is in software, so he’s doing great setting up OpenVR and Perception. The hardware side is a bit new to him. This isn’t stopping [J0nno] though! In true hacker spirit, he’s learning all about resistors and driving LEDs as he works on D.I.Y Virtual Reality.

Next up is [Josh Lindsay] with Digitabulum: The last motion-capture glove. Digitabulum is a motion capture glove designed to be able to emulate most other motion capture systems. It is also designed to be relatively low-cost. At $400 per hand, it is less expensive than most other offerings, though we’d still love to see something even cheaper. [Josh] is going with inertial sensors, and a lot of them. Specifically he’s using no less than 17 LSM9DS1 Inertial Measurement Unit (IMU) sensors from ST Microelectronics. IMU sensors like this combine multiple rate gyros, accelerometers, and magnetometers into a single unit. Essentially every segment of every finger has its own sensor suite. As you might imagine, that is quite a bit of data to crunch. An Altera Max II CPLD and an ST Arm processor help boil down the data to something which a VR engine can process. [Josh] has been working on this project for over a year now, and he’s making great progress. The prototype glove looks terrific!

[Thomas] brings augmented reality to the table with Oculus Rift featured Crane control. What started as a hobby experiment became [Thomas’] major project at university. He’s connected an Oculus Rift to a toy crane. A stereo camera on the crane sends a video image to the operator. The camera is mounted on a pan/tilt mechanism driven by the Rift’s head tracking unit. Simple joystick controls allow [Thomas] to move the boom and lower the line. On-screen displays show the current status of the crane. The use of the Rift makes this an immersive demonstration. One could easily see how moving this system into the real world would make crane operations safer for crane operators.

Finally we have [Arcadia Labs] with DIY Augmented Reality Device. This project, which is the [Arcadia Labs] entry in the 2015 Hackaday Prize, uses two 320 x 240 screens to create an augmented reality head mounted display. While the resolution can’t match that of the Oculus Rift or HTC Vive, [Arcadia Labs] is ok with that. They’re going for a lower cost open source alternative for augmented reality. Tracking is achieved with an IMU, while a PS3 Eye camera provides the video. A Raspberry Pi controls the show. [Arcadia Labs] was able to get 50 frames per second on the displays just using the Pi’s SPI interface, however the USB PS3 Eye camera limits things to around 10 FPS. This project is under heavy development right now, so follow along with us to see where [Arcadia Labs] ends up!

If you want VR goodness, check out our new virtual reality projects list! Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. If you’re on the left coast of the USA, check out SOCAL Virtual Reality Conference and Expo. Hackaday is a sponsor. The event happens on July 12 at the University of California Irvine.

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!

Typewriter Types, Plays Music

June 27, 2015 by Adam Fabio 9 Comments

[Chris Gregg] had a dream. He wanted to convert use a typewriter as a printer. Sure this has been done before, but [Chris] wanted to create his own version. He picked up a 60’s era Smith Corona electric typewriter, with the hopes of driving its key switches with a computer. You can imagine his surprise when he discovered the keys were not electric switches at all, but a complex mechanical system which triggered a clutch to strike the actual paper. Realizing this was not going to be a simple wiring job, [Chris] set the project aside, where it remained for several years.

A conversation with [Bruce Molay], a coworker at Tufts University reignited [Chris’] interest in project. [Bruce] suggested using solenoids to press the keys. [Chris] dove in, and quickly had 48 solenoids on hand. The first problem was mounting the solenoids on the keys. [Chris’] roommate happens to be [Derek Seabury], president of Artisan’s Asylum Hackerspace. [Derek] created an acrylic frame which holds the solenoids and fits directly over the typewriter’s keyboard. This meant that no modifications needed to be made to the typewriter itself. Simply lift off the solenoid array and you’re ready to rock like it’s 1965.

The next step was driving all those solenoids. For that, Chris worked with [Kate Wasynczuk], one of his students at Tufts. [Chris] designed a board using Texas Instruments TPIC6A595 shift registers. The TIPC “power logic” series work like regular 74 series logic, but have seriously beefy outputs. These chips can handle up to 50 volts and 1.5 amps pulsed output current – plenty for [Chris’] 24 volt solenoids. [Chris] taught himself schematic entry and PCB layout in Eagle. After only two tries, he had a working board from OSHPark.

An Arduino Uno converts serial over USB output to a bit stream ready to clock into the shift registers. On the computer side, [Chris] wrote up a basic CUPS driver which allows him to print from his Macbook. The perfect demo for this project turned out to be musical. Click past the break to see The Smith Corona perform “The Typewriter Symphony”, by Leroy Anderson. This may be the first time this particular piece of music has been performed with actual words being typed, rather than random keys.

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