Author: Brian McEvoy

265 Articles

Skylight In Any Room

October 4, 2020 by 41 Comments

Despite a glut of introvert memes, humans need sunlight. If vitamin D isn’t your concern, the sun is a powerful heater, and it helps plants grow. Sadly for [mime], their house is not positioned well to capture all those yummy sunbeams. Luckily for us, their entry into the 2020 Hackaday Prize is their sun-tracking apparatus that redirects those powerful rays throughout the house. It uses a couple of mirrors to redirect the light around their shed and into the house. For those who work in a dim office, no amount of work is too great for a peek of natural sunlight.

Movie spoiler alert: We saw this trick in the 1985 movie Legend and it was enough to vanquish the Lord of Darkness.

This project started in 2014 and sat on hiatus for more than five years, but it is back and prime for improvements fueled by half-a-decade of experience. The parts that aren’t likely to change are the threaded struts that adjust the positioning mirror’s angle, the driving motors, and power circuitry. Their first plan was to build a solar-powered controller with an Arduino, DC motors, and sun telemetry data, but now they’re leaning toward stepper motors and a computer in the house with a long cable. They are a finalist this year, so we will keep our eyes peeled for further development.

The HackadayPrize2020 is Sponsored by:
Supplyframe
Digi-Key
Microchip
Arm

Sunshine In A Bag

October 3, 2020 by 7 Comments

Ultraviolet (UV) curing lamps are crucial if you have a resin 3D printer or work with UV adhesives. Some folks line an old Amazon shipping box with foil and drop a spotlight somewhere inside. Other folks toss their work under the all-natural light source, Sol. Both options have portability and reliability problems, but [AudreyObscura] has it covered with a reflective mat lined with UV strip lights. This HackadayPrize2020 finalist exemplifies the ideal that good ideas are often simple, and this has a remarkably short bill of materials.

Foil bubble insulation is the medium because it provides structure and reflectivity, but it doesn’t cooperate with the LED strip’s adhesive. [AudreyObscura] demonstrates that masking tape as an interfacing layer makes everyone play nicely. A fine example of an experienced maker, their design covers bundling wires and insulating connections to keep everything tidy and isolated. With different arrangements, this can form a tunnel lit from above, a chimney lit from the walls, or you can drape it over some scaffolding.

If you need something a little less portable for your own shop you might consider a mirror-filled chamber. One nice touch to add is a turntable to help make sure the entire part is cured without any missing areas.

Continue reading “Sunshine In A Bag” →

Seek And Ye Shall Command

October 2, 2020 by 3 Comments

If we count all the screens in our lives, it takes a hot minute. Some of them are touchscreens, some need a mouse or keyboard, but we are accustomed to all the input devices. Not everyone can use the various methods, like cerebral palsy patients who rely on eye-tracking hardware. Traditionally, that only works on the connected computer, so switching from a chair-mounted screen to a tablet on the desk is not an option. To give folks the ability to control different computers effortlessly [Zack Freedman] is developing a head-mounted eye-tracker that is not tied to one computer. In a way, this is like a KVM switch, but way more futuristic. [Tony Stark] would be proud.

An infrared detector on the headset identifies compatible screens in line of sight and synchs up with its associated HID dongle. A headset-mounted color camera tracks the head position in relation to the screen while an IR camera scans the eye to calculate where the user is focusing. All the technology here is proven, but this new recipe could be a game-changer to anyone who has trouble with the traditional keyboard, mouse, and touchscreen. Maybe QR codes could assist the screen identification and orientation like how a Wii remote and sensor bar work together.

The HackadayPrize2020 is Sponsored by:
Supplyframe
Digi-Key
Microchip
Arm

Oh, Holey Light

September 30, 2020 by 18 Comments

We consider ourselves well-versed when it comes to the technical literature plastered on hardware store parts. Acronyms don’t frighten us, and our Google-fu is strong enough to overcome most mysteries. One bit of dark magic we didn’t understand was the gobbledygook on LED lamps. Wattage is easy and color temperature made sense because it corresponds with warm and cool colors, but Color Rendering Index (CRI) sounds like deep magic. Of course, some folks understand these terms so thoroughly that they can teach the rest of us, like [Jon] and [Kevin], who are building a light controller that corrects inadequacies in cheap lamps by installing several lamps into one unit.

We learned a lot by reading their logs, which are like the Cliff Notes from a lighting engineer’s textbook, but we’ll leave it as an exercise for the students to read through. Their project uses precise light sensors to measure the “flavor” of light coming off cheap lamps so you can mix up a pleasing ratio. In some ways, they are copying the effects of incandescent bulbs, which emit light relatively evenly across the visible light spectrum, right into the infrared. Unfortunately, cheap LEDs have holes in their spectrum coverage, and a Warm White unit has different gaps compared with Daylight, but combining them just right gives a rich output, without breaking the bank.

The HackadayPrize2020 is Sponsored by:
Supplyframe
Digi-Key
Microchip
Arm

Weigh Your Car With Paper

September 30, 2020 by 23 Comments

Sometimes a problem is more important than its solution. Humans love to solve mysteries and answer questions, but the most rewarding issues are the ones we find ourselves. Take [Surjan Singh], who wanted to see if he could calculate the weight of his Saab 96. Funny enough, he doesn’t have an automobile scale in his garage, so he had to concoct a workaround method. His solution is to multiply the pressure in his tires with their contact patch. Read on before you decide this is an imperfect idea.

He measures his tires with a quality gauge for the highest accuracy and pressurizes them equally. Our favorite part is how he measures the contact patch by sliding a couple of paper pieces from the sides until they stop and then measures the distance between them. He quickly realizes that the treads didn’t contact the floor evenly, so he measures them to get a better idea of the true contact area. Once he is satisfied, he performs his algebra and records the results, then drives to some public scales and has to pay for a weigh. His calculations are close, but he admits this could be an imprecise method due to an n-of-one, and that he didn’t account for the stiffness of the tire walls.

This was a fun thought experiment with real-world verification. If you’re one of those people who treats brainstorming like an Olympic sport, then you may enjoy the gedankenexperiment that is fractals.

Hyper Links And Hyperfunctional Text CAD

September 30, 2020 by 61 Comments

Strong opinions exist on both sides about OpenSCAD. The lightweight program takes megabytes of space, not gigabytes, so many people have a copy, even if they’ve never written a shape. Some people adore the text-only modeling language, and some people abhor the minimal function list. [Johnathon ‘Zalo’ Selstad] appreciates the idea but wants to see something more robust, and he wants to see it in your browser. His project CascadeStudio has a GitHub repo and a live link so you can start tinkering in a new window straight away.

Continue reading “Hyper Links And Hyperfunctional Text CAD” →

Push Pedal For Privacy

September 29, 2020 by 17 Comments

Many of us in the secret Hackaday lair use gaming hardware at our work desks because it is reliable and performs well. We are not alone, and maybe you are reading this on your coffee break over a 20-button mouse. We wager that [Thiago Ribeiro de Azeredo] has this mindset because he converted some old analog gaming pedals into teleconferencing tools for his home office. Now that he is not racing to the office, he has to take a lot of computer calls, and he must quickly and covertly mute his microphone when his howling son tries to take the stage.

The pedals were gathering dust when he started working from home, but they are unretired for the upgrade. Inside, there is no mystery, just a couple of spring-loaded variable resistors, so he adds an Arduino Nano a couple of 4.7 kΩ resistors to create a voltage divider. The Nano doesn’t have native Human Interface Device (HID) functionality, so a Python script receives the serial port signals and toggles an application bar notification so he can see the microphone status. With two pedals, he can press-to-talk or lock his microphone on and off. We have to wonder, did he write the software during a meeting?

We love the idea of controlling our battle stations with our feet or seeing a bunch of RGB keyboards used as a low-res display.

The HackadayPrize2020 is Sponsored by:
Supplyframe
Digi-Key
Microchip
Arm