We all have handfuls of thumb drives lying around with only a vague idea of what’s on most of them, right? So why not dust one off, back it up somewhere, and give it a new purpose? That’s exactly what [Cher_Guevara] did to make this portable Raspberry Pi video looper. The hardest part of recreating this one might be coming up with such a good candidate mini CRT TV.
Once powered on, the Pi Zero W stuffed inside this baby Magnavox waits for a thumb drive to be inserted and says as much in nice green text on the screen. Then it displays the number of video files found on the drive and gives a little countdown before looping them all endlessly.
We love how flawlessly [Cher] was able to integrate the USB port and a flush-mounted shutdown button for the Pi into the TV’s control panel on the top. It’s like a portable from another timeline.
[Cher] got lucky because this TV happens to have a video-in jack for connecting up the Pi. If yours doesn’t have one, you might be able to use an RCA to RF converter if the antenna is removable. We’ve got the demo video waiting for you after these messages.
The breakthrough in bandwidth is attributed to a new optical chip that employs optical frequency combs or micro-comb, and has been published by [Corcoran et al] of Monash University. The team exploits the ability of certain crystals to create resonant optical fields called solitons and these form highly efficient optical transmission system. For the uninitiated, optical frequency combs are an optical spectrum of equidistant lines whose values if fixed, can be used to measure unknown frequencies. The original discovery earned Roy J. Glauber, John L. Hall and Theodor W. Hänsch the Nobel Prize in Physics in 2005, and though it is a relatively new field it has seen a lot of activity in the research community.
The experimental setup has a resonator with a free spectral range spacing of 48.9GHz, and from the generated optical fields or lines, 80 were selected. Using a side-band modulator the bands were doubled and eventually with 64 QAM modulation facilitated a symbol rate of 23 Gigabaud. Now at this point, the paper says that this experiment is still an under-utilization of the available resources. The extra connectivity speed may be helpful in gaming and streaming but we will be needing faster drives to get our emails attachments downloaded faster. If you are inspired and want to play with lasers and optical communications, check out the DIY Laser Optical Link.
We bet you have all some cool part in your bin that is just gnawing at you to build something cool. That doodad, possibly from a garage sale, surplus store, or clearance rack deserves a project fitting of its near-infinite potential. [isaac879] finally marries a giant ball bearing with his passion for photography in the form of a pan-tilt camera mount for his Canon DSLR. The problem with tossing your golden-ticket part into a project is that not everyone has a MacGuffin, or a brand new one might be bank-breakingly expensive, so he does us a favor and makes a drop-in replacement that you can print and fill with 6mm brass bbs. This sort of thing is why we love hackers.
The camera mount has the features we expect to see in a robust stepper mount, such as infinite spinning, time delay, and an Xbox controller interface. Inside the base is the industrial bearing or its plastic replica, and that wide base won’t be tipping over anytime soon. Gearing all around is of the herringbone style, of the type you find in classroom pencil sharpeners because they transfer power smoothly. Speaking of things going smoothly, we enjoyed his assembly montage where every part fits together perfectly and there is not a naughty word to be uttered. Just like real life.
Recreating classic games in software is a great way to get better at coding or learn to code in the first place. If you do it in hardware though, you’ll gain a lot more than coding skills. Just ask [Kelly] and [Jack] did, when they built this Arduino-based electronic Connect Four for a school project.
We love that their interpretation manages to simplify game play and make it more fun than the original version. All the players have to do is turn it on and start pushing the arcade buttons along the bottom to choose the column where they want to make a play. The LEDs animate from top to bottom to imitate the plastic disc dropping down through the board. If a win is detected — four in a row of the same color going any direction — the board fills up with the winning color and the game starts over.
The state machine doesn’t currently do anything about tie situations, so there’s a reset button hidden on the side. As [Kelly] and [Jack] explain in their walk-through video after the break, that is something they would like to address in the future, along with making it possible to choose whatever battle color you want. We think a reset animation that mimics the look of the discs spilling out the bottom would be cool, too.
Back in the early days of disco, filament bulbs were all the rage. Whether tungsten, halogen, or other obscure types, party lighting involved lots of watts and lots of heat. These days, the efficiency of LEDs makes everything a lot cheaper, lighter, and lower power. [Big Clive] decided to dive into a cheap moonflower-type disco light from China, replacing the insides along the way.
The light originally consisted of an 8×8 grid of LEDs, driven by shift registers for a simple chase effect. Surprisingly, the power supply and other hardware inside seemed to at least make an attempt to meet UK regulations. However, [Big Clive] had other plans, whipping up a replacement PCB packing 64 UV LEDs. The video is informative, showing how with a few simple passive components, it’s easy to drive these LEDs from mains without excessive circuitry required to step down to more usual DC voltages.
I will be the first to admit it. This is almost not — at least not specifically — a Linux article. The subject? An automation tool for Chrome or Firefox. But before you hit the back button, hear me out. Sure, this Chrome plugin started out as a tool to automatically test web pages and automate repetitive tasks in the browser. However, it can extend that power to all programs on your computer. So, in theory, you can use it to graphically build macros that can interact with desktop applications in surprisingly sophisticated ways. In theory, anyway; there are a few problems.
The program has a few different names. Most documentation says UI Vision RPA, although there are some references to Kantu, which appears to be an older name. RPA is an acronym for Robotic Process Automation, which is an industry buzz word.
Let’s take it for a spin and see what it’s all about.
When the COVID-19 pandemic unfolded in early 2020, the hacker community responded in the most natural way possible: by making stuff. Isolation and idleness lead to a creative surge as hackers got to work on not only long-deferred fun projects but also potential solutions to problems raised by an overloaded medical system and choked supply chains. And so workshops and hackerspaces the world over churned out everything from novel ventilators to social-distancing aids.
But perhaps the greatest amount of creative energy was set loose on the problem of personal protective equipment, or PPE. This was due in no small part to predictions of a severe shortage of the masks, gowns, and gloves that front-line medical workers would need to keep them safe while caring for pandemic victims, but perhaps also because, at least compared to the complexity of something like a ventilator, building a mask seems easy. And indeed it is as long as you leave unanswered the crucial question: does the thing work?
Answering that question is not as easy as it seems, though. It’s not enough to assume that putting some filtration between the user and the world will work; you’ve got to actually make measurements. Hiram Gay and Lex Kravitz, colleagues at the Washington University School of Medicine in St. Louis, actually crunched the numbers on the full-face snorkel mask they modified for use as a face shield for medical PPE, and they have a lot of insights to share about proper testing of such devices. They’ll join the Hack Chat this week to discuss their findings, offer advice to builders, and reveal how they came up with their idea for a different way to build and test PPE.
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about. Continue reading “PPE Testing Hack Chat”→