Simulating PenTile RGBG Displays

December 9, 2011 by Mike Szczys 22 Comments

Here’s an interesting experiment that lets you simulate PenTile displays on a normal LCD monitor. [Barrett Blackwood] wanted to test out how some graphics look on PenTile RGBG displays with different pixel densities. These PenTile RGBG matrices are sometimes used in OLED displays. For instance, the Nexus One smart phone features a display of this type. Because red, green, and blue OLEDs emit different intensities of light, the pixels are laid out differently from LCD panels in order to balance the color mixing. Our eyes see the green light very well, and so green sub-pixels are made much smaller than their red and blue counterparts.

Because the hardware layout is different, some graphics appear to have crosshatching artifacts in them when viewed on the PenTile displays. [Barrett] made the example above to simulate how graphics look on a traditional LCD screen (image on the left), and how they appear on the PenTile scren (image on the right). The magenta hue seen above is a result of resizing the image. Since the simulation method turns off 1/3 of the green pixels in the image, resizing it ruins the careful calculation. It must be view at a 1:1 ratio to see the image correctly, at which point the magenta magically disappears.

Combine 2 Non-Working Sony TVs Into One That Works

December 7, 2011 by Jeremy Cook 16 Comments

Have you ever wondered if you could fix your two broken LCD TVs by combining them? Neither had we, but [Redion] did, and the answer is yes, it can be done. Although it may sound like a serious kludge, the finished product actually looks quite nice from the view provided. On the other hand, we don’t know how the internals will hold up, but it apparently works well now.

For this hack, the working internals from a 32 inch Sony LCD TV with a broken display were combined with a 40 inch Sony LCD TV that had an undamaged display but fried internals. Although this would most likely not work for every TV out there, it’s still a pretty neat experiment. Many people would simply assume something like this would not work, and trash both TVs. We would suggest the new TV be named “Nomad”, just avoid wearing a red shirt around it.

Keep in mind with any TV hack, taking one apart can expose you to large capacitors that may or may not be charged and can be quite dangerous (they can stay charged for a long time). We don’t necessarily recommend duplicating anything here, but use extreme caution if attempting anything like this.

RCA DSB772WE Teardown Shows That This Cheap Streaming Box Might Have Potential

December 3, 2011 by Mike Nathan 75 Comments

RCA-DSB772WE

[David Anders] wrote in to share some details of a cheap little gadget he picked up at his local Wal-Mart. He scored the RCA DSB772WE media streaming box for $48, and so far it looks like it could be a promising addition to his living room.

He started a project page for the box, detailing some of his findings thus far. The device is MIPS based and runs the Linux kernel version 2.6.28.9 right out of the box. The networking components are based on the Broadcom BCM7615 chipset, though it looks to [David] that the Ethernet jack was removed at some point during production.

So far, he’s managed to get a serial console running on the device, along with an additional USB host connection. That’s about all the poking around he has done thus far, but seeing as the box can output a 1080p signal over HDMI, it could be a cheap substitute for an Apple TV or similar device.

If you happen to have one of these at home, or are planning on buying one, be sure to check out his project page and contribute any information you might be able to glean from it. We’re sure [David] would appreciate it, and we certainly look forward to seeing what else comes out of his hacking adventures.

HDCP Falls To FPGA-based Man-in-the-middle Attack

November 30, 2011 by Mike Nathan 49 Comments

fpga-hdcp-maninthemiddle-attack

It’s been a little while since we talked about HDCP around here, but recent developments in the area of digital content protection are proving very interesting.

You might remember that the Master Key for HDCP encryption was leaked last year, just a short while after Intel said that the protection had been cracked. While Intel admitted that HDCP had been broken, they shrugged off any suggestions that the information could be used to intercept HDCP data streams since they claimed a purpose-built processor would be required to do so. Citing that the process of creating such a component would be extremely cost-prohibitive, Intel hoped to quash interest in the subject, but things didn’t work out quite how they planned.

It seems that researchers in Germany have devised a way to build such a processor on an extremely reasonable budget. To achieve HDCP decryption on the fly, the researchers used a standard off the shelf Digilent Atlys Spartan-6 FPGA development board, which comes complete with HDMI input/output ports for easy access to the video stream in question. While not as cheap as this HDCP workaround we covered a few years ago, their solution should prove to be far more flexible than hard wiring an HDMI cable to your television’s mainboard.

The team claims that while their man-in-the-middle attack is effective and undetectable, it will be of little practical use to pirates. While we are aware that HDMI data streams generate a ton of data, this sort of talking in absolutes makes us laugh, as it often seems to backfire in the long run.

[via Tom’s Hardware]

Gif Player Does It Using Paper Medium

November 23, 2011 by Mike Szczys 4 Comments

Ditch that fancy wide-format LCD monitor and go back to the days when animation was made up of moving frames played back by a specialized device. [Pieterjan Grandry] built this gif player which does just that. The frames of the animation are printed on a paper disk. When spun and viewed through a looking hole the same size as one frame an animated image is formed.

If you know a thing or two about how movie projectors work you might have a raised eyebrow right now. To make the animation smooth you need a way to hide the changing of the frames. With a projector there’s usually a spinning shutter (like a fan) that covers the transition between frames. In this case, [Pieterjan] has mounted the case of the gif player far enough in front of the paper disk that the image is in shadow, making it hard to see. A microcontroller responsible for the speed of the spinning disk flashes some white LEDs with precise timing which gives light to each frame at just the right time.

This is really a 2D equivalent to the 3D stroboscope we saw a few days ago.

[Thanks Agtrier]

Monitoring Batch Jobs The Cylon Way With Python And A Parallel Port

November 18, 2011 by Mike Nathan 14 Comments

parallel-port-trigger

If you happen to do a lot of video encoding, you know that your computer can really drag while the process is carried out. Our own [Mike Szczys] transcodes videos at home fairly often, and because the process is automated, he doesn’t always know if a conversion is taking place in the background.

He has been tinkering with Larson Scanners recently and thought he could put everything he’s learned along the way to good use by using the scanner as a “busy” indicator for his PC. He hooked the scanner up to the computer’s parallel port, and took a few minutes to bang out some Python code that would alert him when his PC was busy.

He set his notifier script to launch along with FFMPEG, whenever his MythTV setup had something ready to convert. The Python script drives a pin on the parallel port high, triggering the Larson Scanner’s animation. Every minute, the script checks the status of FFMPEG and continues to hold the pin high until the application exits. Once the conversion is done, the scanner goes back to sleep, letting [Mike] know that the coast is clear.

Check out the video below the break to see his parallel port trigger in action.

Continue reading “Monitoring Batch Jobs The Cylon Way With Python And A Parallel Port” →

Video: Interrupts On The ATmega328p

November 17, 2011 by Jack Buffington 1 Comment

This week, we are bringing you the final video in our series where [Jack] uses the 3pi robot as a fancy development board for the ATmega328p processor. Today’s video deals with interrupts. If you have been wanting to have your programs do more than one thing simultaneously, interrupts are the solution. [Jack] discusses various ways that you can use interrupts in your programs and then shows how he created a interrupt routine that drives the 3pi’s beeper. He also shows the routines that enable, disable, and control the interrupt.

Since this is the last post for this series of videos, we are posting the code used for all of the previous videos. Click here to grab a copy.

For our next series of videos, we are going to attempt something more challenging so most likely we will be taking a couple of weeks off to do some development before presenting it here. Stay tuned folks, we’ll be back.

Video is after the break…

In case you missed any of the previous videos, check out these links:

Part 1: Setting up the development environment
Part 2: Basic I/O
Part 3: Pulse Width Modulation
Part 4: Analog to Digital conversion
Part 5: Working with the 3pi’s line sensors

Continue reading “Video: Interrupts On The ATmega328p” →