If you’re just getting into hobby electronics chances are there are lots of tools you’d like to get you hands on but can’t yet justify the purchases. Why not build some of the simpler ones? Here’s a great example of a 4-channel logic analyzer that can be your next project and will add to your arsenal for future endeavors.

As you can see, [Vassilis'] creation uses a cellphone-sized LCD screen as the output. It is powered by four rechargeable batteries and driven by an ATmega8 microcontroller. He’s designed the tool without power regulation, relying on the ATmega’s rather wide range of operating voltages, and a few diodes to step down that voltage for the LCD screen.

As you can see in the clip after the break, alligator leads can be used to connect the test circuit to the inputs (don’t forget the ground reference!). Thee buttons at the bottom let you navigate the captured data by panning and zooming. Perhaps the best design feature is the single-sided circuit board which should be quite easy to reproduce at home.

Read the rest of this entry »

[Andy Brown] has been working on a series of tutorials revolving around the STM32 processor family. He’s using the STM32plus development board, with an STM32F1 ARM Cortex M3 processor to drive a couple of different full color graphic LCD screens. His latest installment shows how to read from the touch screen included with both displays.

After the break we’ve embedded the video from which this screenshot was taken. As an example, [Andy] has programmed a painting program to show off what the touchscreen overlay is capable of. It starts off with the calibration routine we’re all familiar with, then drops to this screen with a virtual control panel and blank canvas.

This hardware uses the Texas Instruments ADS7843 controller, which [Andy] says is extremely common and that several other manufacturers use the same communications protocols. He discusses how to communicate with the controller, and how to incorporate the data into your program. Included is an open source library which you can use in your own projects.

Read the rest of this entry »

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.

One of the benefits of working in IT is that there is typically a healthy supply of miscellaneous, half-functioning equipment to mess around with. [Vittore] had an old laptop with a busted LCD sitting around (Google Translation), so he figured he might as well get it to do something useful. With a spare desktop LCD panel and some software tweaking, he built himself a slick network monitoring panel that hangs in his office.

He stripped the laptop down to the bare essentials, and mounted it along with an LCD screen in a plexiglass enclosure. He has Nagios running a server in his office, and with the help of a few plugins, he created a simple web interface that show him the topology of his entire network. The panel itself runs a live version of Debian, which he configured to load up his Nagios web page each time it is started.

While having the ability to view the status of every network-connected device in an instant is great, he didn’t stop there. While browsing around online, he found diagram for a simple USB-based performance monitor that uses a PIC to drive a pair of VU meters. He hooked the meters up to a router monitored by Nagios, so he can watch office’s bandwidth usage in real time.

If you’re interested in seeing how it was built, be sure to check out the Flickr photo set put together by [Vittore’s] co-worker [Matthew].

[dimovi] had a spare LCD monitor sitting around and thought it would be great to convert it into a “privacy” monitor.

The process is simple enough for anyone comfortable with disassembling electronics. He took apart the monitor’s plastic frame, cutting out the polarized film with a utility knife. Once the film was removed, he spent some time removing the film adhesive from the glass panel using a combination of Oops cleaner and paint thinner.

He reassembled the monitor, which now shines a bright white regardless of what is actually being displayed on the screen. He removed the lenses from a pair of theater 3D glasses, replacing the plastic with the film he removed from the monitor.

Now, [dimovi] is the only one who can see what’s he is doing on his computer, which is just the way he likes it.

While there’s not a lot of magic going on behind the process, we think it’s a neat way to reuse an old monitor.

[Dan Rosenfeld] does a lot of thinking in his spare time, and one thing he returns to pretty often is videoconferencing. He’s often wondered why it hasn’t caught on enough to become a ubiquitous piece of technology, and his examination of the topic in regards to eye contact and spatial awareness inspired him to create a very unique Halloween costume.

His “Big Head” costume consists of a front-mounted 24” LCD panel that displays the wearer’s face in real time. Inside the large headpiece [Dan] installed a microphone, another LCD screen, a half silvered mirror, and a video camera – not to mention all of the power-related goodies required to keep it running. While the main LCD displays his face, the internal monitor is fed by an externally mounted camera that shows him everything going on outside the box. This image is reflected off the half silvered mirror, allowing him to gaze directly at the camera, while also seeing what’s going on in front of him.

As you can see in the video below, the effect is pretty cool, and devoid of the ‘disconnected’ look most people have when talking to others via a camera and computer screen.

Read the rest of this entry »

[Will] wrote in to share a useful add-on he designed for the ChipKIT UNO 32, a 12-port temperature sensor board.

Constructed for one of his customers, the shield accepts any 2-wire 10k thermistor sensors, outputting the readings to a small LCD screen. The screen is supported by some code put together by his associate [crenn], but you are not limited to solely displaying the temperatures there. Since this module piggybacks on top of the ChipKIT the same fashion as any standard shield, you clearly have the ability to use and manipulate the data at will. With 12 ports on board this would work well for a house-wide temperature monitoring system, or perhaps in a complex brewing setup.

Both the temperature shield and LCD boards have been released under the Open Source Hardware License, so you can easily build your own if you have the means, though [Will] has a few extras he’s willing to sell if you need one quickly.

Early LCD monitors had some pretty awful issues when not viewed from directly in front of the screen. These days the technology has really minimized this flaw, but if you still have a cheap monitor on hand you might want to pull it out and give this hack a try. [Chris Harrison] is using oblique viewing angles to display additional information on cheap montiors.

Take a look at the two images above. The one on the left is taken from directly in front of the monitor and looks normal. But if you view the same screen from the side, the financial information is obscured. This is by design. Using very light colors, the obscuring characters are almost indiscernible from straight on, but you can just see them there a little bit (they look like burn-in does on a CRT screen). But from the side, these light colors become quite bold and blend with the rest of the data on the screen.

This works because of the polarizing filters on an LCD screen. You might want to watch [Bill Hammack] explain how an LCD works if you’re not familiar. Because the viewing angle color changes are a flaw and not a feature, manufacturers make the up-and-down angles the worst to improve on side-to-side viewing. [Chris'] experiments play into that by using a computer monitor on its side. Check out the video after the break to see some of the different applications that he uses this for.

Read the rest of this entry »