A Different Kind Of IKEA Hack: Javascript Price Comparison By Location

November 14, 2020 by Zoe Skyforest 8 Comments

When looking for the best deal, it pays to shop around. When it comes to chain stores, of course, one expects the price to be the same across their retail network. However, where international companies are concerned, occasionally a better deal is just a border crossing away. To investigate the best possible price on IKEA’s flatpacked goods, [Sn0w5t0rm] whipped up a scirpt to make comparisons easy.

The hack consists of a small piece of Javascript that runs in a browser extension like Greasemonkey (Firefox) or Tampermonkey (Chrome). When visiting an IKEA product page, it shows the price of the same item in the alternative country of your choice. Often, significant savings can be had – the SKOGSTA table is €176 cheaper in the Netherlands compared to Belgium.

While the script does require some customization to suit your location, it could nonetheless save you a bundle on some home furnishings if your live near enough to a border. We’d love to see the concept taken further to tease out best prices in a given region for goods from all stores. Similar techniques can net you cheap airfares, too!

Haunted TV Does Mirror Scares With Raspberry Pi

November 13, 2020 by Zoe Skyforest No comments

Hallowe’en may be over for another year, but that just means you’ve got more time to prepare your build for next time. [gocivici] has a fun twist on the classic mirror scare that might be just up your alley.

The build starts with an old black and white TV, hooked up to a Raspberry Pi 3. The Pi films the scene in front of the television through a camera secreted into the screen’s headphone jack, and displays it on screen. The camera feed is run through OpenCV, which runs face and eye detection algorithms to determine when a person is looking at the screen. Based on a basic timer script, when a viewer has looked long enough, a ghostly apparition is displayed, lurking behind the viewer. When the user looks over their shoulder, the apparition quickly disappears, as per the classical horror trope.

It’s a fun build that would make an excellent set piece for your next Hallowe’en party. For extra effect, be sure to secret it down a dark hallway with some IR LEDs illuminating the scene for the camera only. If you prefer something with a little more whimsy, consider these animated singing pumpkins instead. Video after the break.

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“Artificial Sun” Lighting Via Old Satellite Dishes

November 13, 2020 by Zoe Skyforest 53 Comments

Real sunlight is a beautiful thing, but due to the vagaries of Earth’s orbit and local weather systems, it’s not available all the time. [Matt] decided this wasn’t good enough, and set about building a rig to replicate the sun’s rays as closely as possible.

Rayleigh scattering is emulated by passing the light through a glass chamber filled with soapy water – taking advantage of the Tyndall effect.

The great distance between the Sun and the Earth means that the sun’s rays are essentially parallel from our local vantage point. Replicating this, and the soothing nature of a blue sky, were [Matt]’s primary goals with the project. To achieve this, an old satellite dish was pressed into service as a parabolic reflector, coated with mirror-finish vinyl strips. A 500W white LED with a good color rendering index was fitted at the focal point, outfitted with a water cooling system to shed heat. With a point source at its focal point, the parabolic reflector bounces the light such that it the rays are parallel, giving the sense that the light source is coming from an effectivelyl infinite distance away. To then achieve the blue sky effect, the light was then passed through a glass chamber filled with soapy water, which scatters the light using the Tyndall effect. This mimics the Rayleigh scattering in Earth’s atmosphere.

The final result is amazing, with [Matt] shooting footage that appears to be filmed in genuine daylight – despite being shot at night or on rainy days. He also features a cutdown build that can be achieved in a far cheaper and compact form, using Fresnel lenses and blue film. We’ve featured [Matt]’s daylight experiments before, though we’re amazed at the new level reached. Video after the break.

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Zoom Control Box Helps Keep Meetings On Track

November 13, 2020 by Zoe Skyforest 19 Comments

For many people, the biggest change of 2020 has been adjusting to a glut of online teleconferences as a part of daily working life. [p_leriche] has had to adjust the way church services are conducted, and found managing a complicated streaming meeting setup to be complicated at best. To ease the workload on the presenter, he created a simple Zoom control box.

At its heart, the box is little more than a fancy keyboard. An Arduino Pro Micro is hooked up to a series of brightly colored pushbuttons, each labelled with regularly used Zoom functions. The Pro Micro is programmed to fire off the corresponding keyboard shortcuts when the buttons are pressed, activating the relevant function.

It might be a simple build, but it greatly reduces the hand gymnastics required mid-presentation, and we’re sure the users greatly appreciate the new hardware. While this is a quick-and-dirty build thrown together in a basic enclosure, macro keyboards can be both useful and attractive if you so desire. If you’ve built your own time-saving control console, be sure to let us know!

Easy Carrier Board For The Compute Module 4 Shows You Can Do It, Too

November 13, 2020 by Zoe Skyforest 25 Comments

The Raspberry Pi Compute Module 4 has got many excited, with a raft of new features bringing exciting possibilities. However, for those used to the standard Raspberry Pi line, switching over to the Compute Module form factor can be daunting. To show just how easy it is to get started, [timonsku] set about producing a quick and dirty carrier board for the module at home.

The Twitter thread goes into further detail on the design of the board. The carrier features HDMI, USB-A and USB-C ports, as well as a microSD slot. It’s all put together on a single-sided copper PCB that [timonsku] routed at home. The board was built as an exercise to show that high-speed signals and many-pin connectors can be dealt with by the home gamer, with [timonsku] sharing tips on how to get the job done with cheap, accessible tools.

The board may look rough around the edges, but that’s the point. [timonsku] doesn’t recommend producing PCBs at home when multi-layer designs can be had cheaply from overseas. Instead, it serves to show how little is really required to design a carrier board that works. Even four-layer boards can be had for under $10 apiece now, so there’s never been a better time to up your game and get designing.

For those eager to learn more about the CM4, we’ve got a full breakdown to get you up to speed!

Domino Clock Tells The Time In Style

November 12, 2020 by Zoe Skyforest 11 Comments

It seems there are as many ways to display the time as there are ways to measure it in the first place. [Kothe] saw a fancy designer domino clock, and wanted a piece of the action without the high price tag. Thus, the natural solution was to go the DIY route.

An Arduino Nano is the heart of the build, paired with a DS1307 RTC for accurate timekeeping. The case of the clock consists of a 3D printed housing, fitted with layers of lasercut acrylic. Behind this, a smattering of WS2812B addressable LEDs are fitted, which shine through the translucent grey plastic of the front panel. This enables each LED to light up a dot of the domino, while remaining hidden when switched off. Reading the time is as simple as counting the dots on the dominoes. The first domino represents hours, from 1 to 12, while the second and third dominoes represent the minutes.

As a timepiece, the domino clock serves well as a stylish decor piece, and could also be a fun way to teach kids about electronics and telling the time. Makers do love a good timepiece, and our clock tag is always overflowing with fresh hacks on a regular basis. If you’ve got your own fancy build coming together at home, you know who to call!

Highly Sensitive Camera Makes A Great Night Vision Scope

November 12, 2020 by Zoe Skyforest 18 Comments

Traditional military-grade nightvision gear has a history stretching back to the Second World War, relying on photomultiplier tubes to help soldiers see in the dark. Such devices have trickled down to the civilian market in intervening years, however other simpler techniques can work too. [Happy_Mad_Scientist] whipped up a simple nightvision monocular using a very sensitive camera instead.

Due to the high noise, still photos don’t do it justice. The video quality is highly impressive for a system running with no IR illumination.

The camera in question is the Runcam Night Eagle 2, prized for its 0.00001 lux sensitivity. Black and white only, its capable of providing vision in moonlight and starlight conditions without external illumination. In this project, it’s hooked up to a monocle display designed for use with drone FPV setups. With lithium batteries and a charge circuit hooked up, and everything stuffed inside a compact 3D printed case, the final result is a portable, pocket sized night vision device for under $200 USD.

[Happy_Mad_Scientist] notes that in starlight conditions, it provides an advantage over other nighttime Airsoft players relying on IR illumination to see in the dark. We can imagine it would perform well in concert with a bright IR headlamp for those times when there’s simply no ambient light available – particularly indoors.

If your tastes are more military-spec, consider this teardown of a high-end Norweigan device. Video after the break.

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