Hackaday Links: February 16, 2021

This is it; after a relatively short transit time of eight months, the Mars 2020 mission carrying the Perseverance rover has almost reached the Red Planet. The passage has been pretty calm, but that’s all about to end on Thursday as the Entry Descent and Landing phase begins. The “Seven Minutes of Terror”, which includes a supersonic parachute deployment, machine-vision-assisted landing site navigation, and a “sky-crane” to touch the rover down gently in Jezero crater, will all transpire autonomously 480 million km away. We’ll only learn about how it goes after the eleven-minute propagation delay between Mars and Earth, but we’ll be glued to the NASA YouTube live stream nonetheless. Coverage starts on February 18, 2021 at 11:15 AM Pacific Standard Time (UTC-8). We’ve created a handy time zone converter and countdown so you don’t miss the show.

As amazing as the engineering on display Thursday will be, it looks like the US Navy has plans to unveil technology that will make NASA as relevant as a buggy-whip company was at the turn of the last century. That is, if you believe the “UFO Patents” are for real. The inventor listed on these patents, Dr. Salvatore Pais, apparently really exists; he’s had peer-reviewed papers published in mainstream journals as recently as 2019. Patents listed to Dr. Pais stretch back to 2004, when he invented a laser augmented turbojet propulsion system, which was assigned to defense contractor Northrup Grumman. The rest of the patents are more recent, all seemingly assigned to the US Navy, and cover things like a “high-frequency gravitational wave generator” and a “craft using an inertial mass-reduction device”. There’s also a patent that seems to cover a compact fusion generator. If any of this is remotely true, and we remain highly skeptical, the good news is that maybe we’ll get things like the Epstein Drive. Of course, that didn’t end well for Solomon Epstein. Or for ManĂ©o Jung-Espinoza.

Of course, if you’re going to capitalize on all these alien patents, you’re going to need some funding. If you missed out on the GME short squeeze megabucks, fret not — there’s still plenty of speculative froth to go around. You might want to try your hand at cryptocurrency mining, but with GPUs becoming near-unobtainium, you’ll have to get creative, like throwing together a crypto mining farm with a bunch of laptops. It looks like the Weibo user who posted the photos has laptops propped up on every available surface of their apartment, and there’s also a short video showing a more industrial setup with rack after rack of laptops. These aren’t exactly throw-aways from some grade school, either — they appear to be brand new laptops that retail for like $1,300 a pop. The ironic part is that the miner says this is better than the sweatshop he used to work in. Pretty sure with all that power being dissipated in his house, it’ll still be a sweatshop come summer.

A lot of people have recently learned the hard lesson that when the service is free, you’re the product, and that what Google giveth, Google can taketh away in a heartbeat, and for no discernable reason. Indie game studio Re-Logic and its lead developer Andrew Spinks found that out last week when a vaguely worded terms-of-service violation notice arrived from Google. The developer of the popular game Terraria was at a loss to understand the TOS violation, which resulted in a loss of access to all the company’s Google services. He spent three weeks going down the hell hole of Google’s automated support system, getting nothing but canned messages that were either irrelevant to his case or technically impossible; kinda hard to check your Gmail account when Google has shut it down. The lesson here is that building a business around services that can be taken away on a whim is perhaps not the best business plan.

And finally, we watched with great interest Big Clive’s secrets to getting those crisp, clean macro shots that he uses to reverse-engineer PCBs. We’ve always wondered how he accomplished that, and figured it involved some fancy ring-lights around the camera lens or a specialized lightbox. Either way, we figured Clive had to plow a bunch of that sweet YouTube cash into the setup, but we were surprised to learn that in true hacker fashion, it’s really just a translucent food container ringed with an LED strip, with a hole cut in the top for his cellphone camera. It may be simple, but you can’t argue with the results.

Continue reading “Hackaday Links: February 16, 2021”

Mercurial Light Box Has A Secret Switch

Hit up the lighting aisle of any big box hardware store these days and you’ll probably find a variety of Edison bulbs — modern bulbs meant to evoke the bare, complicated tungsten filament bulbs from the early days of electric candlelight. Edison bulbs use filament LEDs, which resemble skinny candles with wicks at both ends and give off a nice light, especially when diffused by acrylic.

This simple light box uses two filament LEDs that float inside on an internal circuit sculpture. [lonesoulsurfer] likes to use old cell phone batteries and USB charging boards in his builds, and that’s exactly what’s inside this box.

Our favorite part of the build elevates this simple light box into a curiosity for those not in the know. It’s controlled with a mercury tilt switch, so all you’d have to do in a power outage is locate the box and turn it upside down, provided it has a charge.

We love elemental switch design around here, like this light box that switches on with salt water.

DIY ZigBee Therapy Lights Are Hue Compatible

Working on a project into the wee hours is hardly uncommon for us hackers, but if you’re consistently sleeping until the afternoon, it’s possible you’re suffering from a condition known as Delayed Phase Sleep Disorder (DPSD). Put simply, your body’s internal clock is out of alignment with the world around you. One of the ways to treat this condition is to expose yourself to bright light in the morning, which can help you wake up and feel more refreshed. Unfortunately, these so-called “Bright Light Therapy” boxes tend to be pretty expensive.

Looking for a way to treat his own DPSD, [Edward Shin] decided to build his own light box based on the research he’d done on the various commercial offerings out there. After all, a box full of bright lights that operates on a timer doesn’t seem particularly complex. Of course, in reality there’s a bit more to it than that, but so far the results are certainly promising.

The first decision [Edward] had to make was what kind of light he wanted. Classic light therapy devices, often used to treat Seasonal Affective Disorder (SAD), tend to be full spectrum lights that try and simulate sunlight. But in his research, he found a paper from Nature that explained the melanopsin in the human eye responds primarily to blue and green light. But as intense blue light can apparently lead to macular degeneration, he decided to go with green.

Since [Edward] already uses the Philips Hue system for his home’s lighting, he wanted to bring his therapy light into that ecosystem. The idea was that he could easily schedule his new green light box to go on when he wanted to wake up in the morning. So he used the Mesh Bee from Seeed Studio which not only supports ZigBee, but for which software is available to emulate a Hue bulb. Then he just needed to pair that with a sufficiently beefy LED driver and some 510 nm emitters. Everything is enclosed in a box made of laser cut wood that’s designed to hang from the headboard and shine down onto his face.

Over the years we’ve seen a number of similar projects trying to address SAD, so the idea of a hacker tweaking the concept to tackle DPSD seems a natural enough evolution of the idea. Just remember to speak with a medical professional before coming up with a homebrew treatment plan.

Decorative Light Box Lets You Guess The Time

Telling time by using the current position of the sun is nothing revolutionary — though it probably was quite the “life hack” back in ancient times, we can assume. On the other hand, showing time by using the current position of the sun is what inspired [Rich Nelson] to create the Day Cycle Clock, a color changing light box of the Philadelphia skyline, simulating a full day and night cycle in real time — servo-controlled sun and moon included.

At its core, the clock uses an Arduino with a real-time clock module, and the TimeLord library to determine the sunrise and sunset times, as well as the current moon phase, based on a given location. The sun and moon are displayed on a 1.44″ LCD which doubles as actual digital clock in case you need a more accurate time telling after all. [Rich] generally went out of his way with planning and attention to detail in this project, as you can see in the linked video, resulting in an impressively clean build surely worthy as gift to his brother. And if you want to build one for yourself, both the Arduino source code and all the mechanical parts are available on GitHub.

An interesting next iteration could be adding internet connectivity to get the current weather situation mixed into the light behavior — not that it would be the first time we’d see weather represented by light. And of course, simulating the northern lights is also always an option.

Continue reading “Decorative Light Box Lets You Guess The Time”

DIY Lamps Brighten Winter Blues

As you know, winter is coming. For a lot of people this means that Seasonal Affective Disorder is beginning to set in. [Luke]’s mom already has a light therapy box. It’s one of those commercially available ones that uses fluorescent bulbs and leaves a lot to be desired in the full-spectrum light simulation department. [Luke] jumped on the opportunity to design a better one.

The standard of quality for light therapy units is a rating of 10,000 lux. While lux definitely matters, the rating is a misleading selling point when given on its own. One of the other important factors in mimicking the sun is the Color Rendering Index (CRI). CRI is basically a rating of the bulb’s ability to imitate the color reproduction of natural daylight. The ratings run from 0 to 100 but in reality, the highest-rated bulbs of any kind top out around 98.

For all the fluorescent bulb-bearing light therapy units out there, those bulbs have pretty low CRI ratings. [Luke]’s project page provides emission spectra graphs for a number of bulb types, and we can see how his choice of ceramic metal halide bulbs stacks up against fluorescent, incandescent, and LED bulbs. One of the few downsides to this type of bulb is that they have long startup times.

He ended up making two light therapy lamps, one of them directional and the other omni-directional. They both use ballast-controlled ceramic metal halide bulbs. The ballasts are necessary to provide the high starting voltage that these bulbs require. The omni-directional light is built into a large hurricane candle holder. A lamp holder is fixed into the base and wired to an external ballast box. The directional lamp is a self-contained unit, and [Luke] is happiest with this one. It’s flat and rugged so it can be placed on top of a bookcase and the light bounced off of the ceiling for pleasant, indirect coverage.

We’ve seen a couple of alarm-clock wakeup light builds here, and we’re thinking this would make an awesome mashup.

Built-in Coffee Table Lightbox

diydollarstorelightbox

[Flyingpuppy] sent us this tip about her cleverly-concealed pull-out lightbox drawer. Her resolution for the new year was to make more art, so she filled this coffee table with art supplies and decided she’d draw while relaxing in front of the television. She also wanted a lightbox nearby, which originally involved hacking the entire tabletop with some acrylic, but she eventually opted for a simpler build: and it’s portable, too! The drawer’s lights are battery-powered, so you can pull the entire thing out of the table and drag it onto your lap, if that makes drawing more comfortable.

[Flyingpuppy] sourced seven inexpensive LED units from her local dollar store, which she mounted to the back of the drawer with some screws. The rest of the drawer was lined with white foam board, the bottom section angled to bounce light up onto the acrylic drawing surface. Because she needs to open the case to manually flip on the lights, she secured the acrylic top magnetically, gluing a magnet to the underside of the foam board and affixing a small piece of steel to the acrylic. A simple tug on the steel bit frees the surface, providing access underneath. Stick around for a video below.

Continue reading “Built-in Coffee Table Lightbox”

Portable Light Box For Small Photography Needs

[Paulo] needed to photograph small objects on the go. Since you can’t always depend on ambient lighting conditions he built a battery operated light box which is easy to take along on his travels.

We’ve featured portable light tents before, but they still tend to be a bit too bulky for his tastes. He chose to go with a white plastic storage container from Ikea. It’s lightweight, and acts as a diffuser for the light sources. Four strips, each hosting three LEDs, were mounted on the exterior of the container. Half of a PVC pipe protects the boards while providing a way to fasten the strips in place using nuts and bolts. The driver board and batteries find a home inside of a travel container for a bar of soap.

He likes the results, especially when a glossy white piece of paper is used as a top reflector.