Monochrome CRT And Liquid Crystal Shutter Team Up For Color Video

October 1, 2019 by Dan Maloney 21 Comments

If you were tasked with designing a color video monitor, it’s pretty clear how you’d go about it. But what if you’d been asked to do so 20 years ago? Would it have been a cut and dried from an engineering standpoint? Apparently not, as this hybrid LCD-CRT video monitor demonstrates.

We’d honestly never heard of this particular design, dubbed “LCCS”, or liquid crystal color shutter, until [Technology Connections]’ partial teardown of the JVC monitor and explanation of its operation. The idea is simple and hearkens back to the earliest days of color TV in the United States, when broadcasters were busy trying to bring color to a monochrome world in a way that would maximize profits. One scheme involved rotating a color wheel in front of the black-and-white CRT and synchronizing the two, which is essentially what’s happening in the LCCS system. The liquid crystal panel cycles between red, blue, and green tints in time with the CRT’s images behind it, creating a full-color picture. “But wait!” you cry. “Surely there were small color CRTs back in the year 2000!” Of course there were, but they kind of sucked. Just look at the comparison of a color CRT and the LCCS in the video below and you’ll see why this system carved out a niche in the pro video market, especially for video assist monitors in the days before digital cinematography. A similar system was used by Tektronix for color oscilloscopes, too.

As usual, [Technology Connections] has managed to dig up an interesting bit of the technological fossil record and present it in a fascinating way. From video on vinyl to 1980s copy protection to the innards of a toaster, we enjoy the look under the hood of forgotten tech.

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Toilet Seat Could Save Your Ass

February 12, 2019 by Brian McEvoy 20 Comments

Our morning routine could be appended to something like “breakfast, stretching, sit on a medical examiner, shower, then commute.” If we are speaking seriously, we don’t always get to our morning stretches, but a quick medical exam could be on the morning agenda. We would wager that a portion of our readers are poised for that exam as they read this article. The examiner could come in the form of a toilet seat. This IoT throne is the next device you didn’t know you needed because it can take measurements to detect signs of heart failure every time you take a load off.

Tracking heart failure is not just one test, it is a buttload of tests. Continuous monitoring is difficult although tools exist for each test. It is unreasonable to expect all the at-risk people to sit at a blood pressure machine, inside a ballistocardiograph, with an oximeter on their fingers three times per day. Getting people to browse Hackaday on their phones after lunch is less of a struggle. When the robots overthrow us, this will definitely be held against us.

We are not sure if this particular hardware will be open-source, probably not, but there is a lesson here about putting sensors where people will use them. Despite the low rank on the glamorous scale, from a UX point of view, it is ingenious. How can we flush out our own projects to make them usable? After all, if you build a badass morning alarm, but it tries to kill you, it will need some work and if you make a gorgeous clock with the numbers all messed up…okay, we dig that particular one for different reasons.

Via IEEE Spectrum.

Eyes On The Prize Of Glucose Monitoring

December 6, 2018 by Brian McEvoy 18 Comments

People with diabetes have to monitor their blood regularly, and this should not be a shock to anyone, but unless you are in the trenches you may not have an appreciation for exactly what that entails and how awful it can be. To give a quick idea, some diabetics risk entering a coma or shock because drawing blood is painful or impractical at the moment. The holy grail of current research is to create a continuous monitor which doesn’t break the skin and can be used at home. Unaided monitoring is also needed to control automatic insulin pumps.

Alphabet, the parent company of Google, gave up where Noviosense, a Netherlands company owned by [Dr. Christopher Wilson], may gain some footing. Instead of contact lenses which can alter the flow of fluids across the eye, Noviosense places their sensor below the lower eyelid. Fluids here flow regardless of emotion or pain, so the readings correspond to the current glucose level. Traditionally, glucose levels are taken through blood or interstitial fluid, aka tissue fluid. Blood readings are the most accurate but the interstitial fluid is solid enough to gauge the need for insulin injection, and the initial trial under the eyelid showed readings on par with the interstitial measurements.

Hackers are not taking diabetes lying down, some are developing their own insulin and others are building an electronic pancreas.

Via IEEE Spectrum.

ESP8266 Monitor Keeps An Eye On OctoPrint

November 5, 2018 by Tom Nardi 8 Comments

At this point, you’ve almost certainly heard of OctoPrint. The web-based control interface for 3D printers is especially popular for those who’s primary computers run on an operating system that has a penchant for occasionally imploding. Even if you aren’t laboring under that common software handicap, OctoPrint offers a wide away of compelling features. Perhaps chief among them the ability to monitor your printer over the network, and if you insist, over the Internet. But while OctoPrint provides the server side for getting your printer on the net, you’re on your own for the client.

Rather than using a web browser like some kind of peon, [David Payne] has come up with a very slick desktop OctoPrint monitor using the WeMos D1 Mini ESP8266 board. With an exceptionally low part count and housed in a (what else) 3D printed enclosure, this is a cheap and easy OctoPrint accessory that we suspect will be decorating many a hacker’s desk before too long.

The electronics are simple to the extreme, just hook the 4 wires of an 128×64 OLED I2C display to the appropriate pins of the ESP8266 board, and you’re ready to upload the Arduino code [David] has come up with.

His code is very polished, from using WiFiManager for initial network setup to providing its own web-based configuration menus to get the device linked up to your OctoPrint instance, [David] clearly wanted this to be as smooth an experience as possible for the end user. When the 3D printer isn’t working on a job, the monitor will even switch over to showing you the time and weather. We’ve seen commercial products that weren’t this user-friendly.

We also love the case design on this little gadget. While the aesthetics are perhaps debatable (sort of reminds us of the little fellows from Darwinia), we appreciate any functional print that doesn’t require supports. You’ll need to provide a couple of little screws to keep the back panel on, but other than that everything snaps into place.

Of course, you could always just use your smartphone to keep an eye on OctoPrint, and even if the remote management capabilities don’t grab your interest, there’s plenty of interesting plugins to keep you occupied.

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A Custom Built FPV Monitor To Keep The Fans Happy

September 5, 2018 by Tom Nardi 7 Comments

If you’re going to be flying around a FPV-capable aircraft, be it a quadcopter or a fixed-wing plane, you shouldn’t be surprised if bystanders want to take a turn wearing your googles. Of course we hope that you’re good enough flying line of sight that you don’t need to be wearing the googles to stay airborne, but it does make it harder to pull off the sort of tricks and maneuvers that your audience wants to see. So if you want to put on a good show, the audience really needs their own display.

Unfortunately, as avid FPV flier [Michael Delaney] discovered, even the “cheap” ones will run you at least $100 USD. So he did what any self-respecting hacker would do, he set out to build his own. Using a collection of off the shelf components he was able to build a very impressive monitor that lets the viewer see through the eyes of his quadcopter at less than half the cost of commercially available offerings. Though even if he hadn’t manged to beat the cost of a turn-key monitor, we think it would have been more than worth it for this piece of highly customized gear.

At the heart of the monitor is a Boscam RX5808 5.8 GHz receiver, which is controlled by an Arduino Pro Mini. The video output from the receiver is sent to a 4.2″ TFT screen intended for the Raspberry Pi, and on the backside of the laser-cut wooden enclosure there’s a 128 x 64 I2C OLED to display the currently selected channel and diagnostic information.

An especially nice touch for this project is the custom PCB used to tie all the components together. [Michael] could have taken the easy route and sent the design out for fabrication, but instead went with the traditional method of etching his own board in acid. Though he did modernize the process a bit by using a laser and pre-sensitized copper clad board, a method that seems to be gaining in popularity as laser engravers become a more common component of the hacker’s arsenal.

We’ve previously covered using the RX5808 and Arduino combo to create a spectrum analyzer, in case you want to do more than just watch your friends do powerloops.

3D Printer Guardian Watches For Worst-case Failures

July 16, 2018 by Donald Papp 17 Comments

Some devices have one job to do, but that job can have many facets. To [jmcservv], an example of this is the job of protecting against worst-case failures in a 3D printer, and it led him to develop the 3D Printer Watchdog Guardian. When it comes to fire, secondary protection is the name of the game because it’s one thing to detect thermal runaway and turn off a heater, but what if that isn’t enough? The MOSFET controlling the heater could have failed closed and can no longer be turned off in a normal sense. In such cases, some kind of backup is needed. Of course, a protection system should also notify an operator of any serious problem, but what’s the best way to do that? These are the kinds of issues that [jmcservv] is working to address with his watchdog, which not only keeps a careful eye on any heating elements in the system, but can take a variety of actions as a result.

Some outcomes (like fire) are bad enough that it’s worth the extra work and cost of additional protection, and that’s the thinking that has led [jmcservv] to submit his watchdog system for The Hackaday Prize.

Trashed Vector Game Console Revived With Vintage IBM Monitor

June 1, 2018 by Dan Maloney 9 Comments

We’ve all had the heartbreak of ordering something online, only to have it arrive in less than mint condition. Such are the risks of plying the global marketplace, only more so for used gear, which seems to be a special target for the wrath of sadistic custom agents and package handlers all along the supply chain.

This cruel fate befell a vintage Vectrex game console ordered by [Senile Data Systems]; the case was cracked and the CRT was an imploded mass of shards. Disappointing, to say the least, but not fatal, as he was able to make a working console from the remains of the Vectrex and an old IBM monitor. The Google translation is a little rough, but from what we can gather, the Vectrex, a vector-graphics console from the early 80s with such hits as MineStorm, Star Castle, and Clean Sweep, was in decent shape apart from the CRT. So with an old IBM 5151 green phosphor monitor, complete with a burned-in menu bar, was recruited to stand in for the damaged components. The Vectrex guts, including the long-gone CRT’s deflection yoke assembly, were transplanted to the new case. A little room was made for the original game cartridges, a new controller was fashioned from a Nintendo candy tin, and pretty soon those classic games were streaking and smearing across the long-persistence phosphors. We have to admit the video below looks pretty trippy.

If arcade restorations are your thing, display replacements like this are probably part of the fun. Here’s a post about replacing an arcade display with a trash bin CRT TV, an important skill to have is this business.

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