A high-resolution LCD or OLED screen is a commodity component that we can buy on a little breakout board and plug into our microcontrollers without spending more than a dollar or two. We can buy them in sizes ranging from sub-postage-stamp to desktop TV if our budgets stretch that far, and they are easy to drive in every sense of the word. It is not so long ago though that a high-resolution LCD, even a small one, was a seriously expensive component. In consumer electronic devices such as camcorders engineers went to great lengths to avoid those costs, and [12voltvids] recently took a look at one of them.
Inside the viewfinder of a miniaturized Sony camcorder is a CRT. It’s fairly mundane in the scheme of CRTs, in that it’s a monochrome device with no unexpected features. Except that is, for one thing. It’s tiny, with only a 0.5″ inch screen size. Everything else is the same as your vintage full-sized TV, it has an electron gun and a deflection and focusing coil pack, but the entire device has been miniaturized to the point at which the coil pack is larger than the screen it is driving. On the accompanying PCB are all the support circuits, including a tiny flyback transformer and a single IC – a Rohm BA7149 electronic viewfinder driver that is as near as possible an entire CRT TV on a chip. That’s it, the whole device runs from a single 5 volt supply.
He doesn’t give the date of the camcorder, but given that it looks as though it uses 8mm cassette tapes and has a curved miniaturized design rather than the angular black exteriors that were fashionable earlier we’d guess it to be from some time around the year 2000. To give it some context, at the time one of the hottest pieces of consumer electronics would have been a Diamond Rio MP3 player, and if your desktop PC had the first of the AMD Athlon processors you probably considered it to be about the fastest you could hope to own. The surprise then is that Sony still considered it more economical even at that point to use the CRT and associated circuitry than a tiny LCD. Either way we’d agree with him that it’s a keeper, a fascinating curio for any electronics enthusiast. If we see an old camcorder going for not a lot, we’ll certainly give it a second look after this.
Continue reading “A Look At The Smallest Magnetic Deflection CRT Ever Made”
As we read [Adam]’s writeup for an extremely tiny video game system through coke bottle glasses, we’re reminded of the countless times we were told that sitting, ‘too close to the Nintendo’ would ruin our eyes. We’ll happily dismiss any article from a medical journal that says there was any truth to that statement, but [Adam]’s tiny video game system will most certainly hurt your eyes.
A few years ago, Atari sold keychain-sized joysticks that contained classics such as Pong, Breakout, Centipede, and Asteroids. [Adam] apparently ran into a cache of these cool classic baubles and immediately thought of turning them into a stand-alone video game system.
For the display, [Adam] used a CRT module from an old Sony Handicam. These modules had the right connections – power, ground, and composite video input – to connect directly to the Atari keychain games. The result is a video game that’s even smaller than a postage stamp. The picture above shows the tiny CRT next to a 25mm postage stamp; it’s small by any measure.
Every smartphone (and most dumb phones) has a video camera built into it these days. Some of them are even capable of recording respectable HD video. So we’d bet that the decades old camcorder you’ve got kicking around isn’t getting any use at all anymore. [John] wants to encourage you to hack that hardware. He published a post showing just how easy it is to salvage and use a camcorder CRT.
The gist is that you simply need to hook up power and feed it video. The board that is attached to the CRT has its own voltage hardware to drive the tube. He demonstrates a 9V battery as a power supply, but also mentions that it should be pretty easy to power the thing from a USB port. As for video, all it takes is a composite signal. Of course you’ve got to determine the pinout for your particular CRT module. The method he chose was to use a continuity tester to find the path from a capacitor’s negative leg to the appropriate pin header. Next he used a bench supply to inject a current-limited low voltage until he saw response when probing the pins. Finding the composite-in is a similar trial and error process.
So what can you use this for? Why not make it the display for a simple video game?
Who needs a tactile interface when you can wave your hands in the air to make music? Air String makes that possible and surprisingly it does so without the use of a Kinect sensor.
In the image above, you can see that two green marker caps are used as plectra to draw music out of the non-existent strings. Judiciously perched atop that Analysis and Design of Digital Systems with VHDL textbook is a camcorder recording an image of the player. This signal is processed by an FPGA (hence the textbook) in real-time, and shown on the monitor seen to the right. A set of guides are overlaid on the image, so the player knows where to pluck to get the notes she is expecting.
The program is designed to pick up on bright green colors as the inputs. It works like a charm as you can see in the video after the break. The team of Cornell students responsible for the project also mention a few possible improvements like adding a distance sensor (ultrasonic rangefinder?) so that depth can be used for the dynamics of the sound.
Continue reading “Get ready to play some wicked air harp”
[Snypercat] makes no bones about the fact that she despises rats, and does everything in her power to keep them off her farm. We can’t blame her though – they spread disease, eat other animals’ food, and can get your farm shut down if there are too many running about. While most of us might hire an exterminator or set out a ton of traps, she chooses to take a far more hands-on approach, hunting down each and every one of those little buggers with an air rifle.
If you’ve ever gone rat hunting in the dark (and who hasn’t?), you know that it can be difficult to aim in the dead of night. Night vision scopes can be expensive, but [Snypercat] shows how you can make your own scope that gives you the added benefit of recording your kills along the way. She happened to have a Sony camcorder with built-in night vision capabilities, and with a bit of tweaking she was able to mount it on her rifle’s scope. An IR flashlight was mounted on the rifle as well, giving her enhanced visibility without spooking her prey.
Be sure to check out the pair of videos below to see how [Snypercat] attached the camcorder to the scope, along with how well it works in the field.
Continue reading “Hunting down farmyard pests with technology”
This interesting mashup shows it’s easy to make your own night vision goggles. It makes use of just a few parts; the viewfinder from an old camcorder, a low-light security camera module, and a collection of infrared LEDs.
The low-light camera is capable of detecting infrared light, which is invisible to our eyes. If you shine the right IR LEDs on an object, they will cast enough light for the camera to clearly view the objects around you. The camcorder viewfinder is nothing more than a compact way to display what the camera sees. This would be easy to accomplish with a wearable display. It is also beneficial to have a large IR light source so you may consider modifying that giant LED flashlight you’ve been meaning to build so that it operates in the infrared wavelengths.
This project comes from the same source as the Laser Microphone we looked in on last month. Just like that one, there’s plenty of extra information about this build. There’s suggestions for choosing and focusing a light source. This includes using lasers as the source, and binoculars for long-range viewing.
Who doesn’t need to take pictures of the microscopic bits inside of an integrated circuit? [Mojobojo] made an end-run around the expensive equipment by building a microscopic lens from an old camcorder. He’s using a regular digital camera with the lens set to its largest zoom level. The camera is pointed into the salvaged camcorder lens where the fine tuning is done. His first iteration was just taped to the desk with a small hand flashlight illuminating the subject. He upgraded that setup by building a LEGO enclosure and changing to a much brighter light source. The images he’s getting are quite surprising and this will be very useful during those extreme hacks when you need to tap into an IC’s internal data rails.