Misc Hacks

4183 Articles

Displaying The Rainbow

February 20, 2026 by 3 Comments

True or false? Your green laser pointer is more powerful than your red one. The answer is almost certainly false. They are, most likely, the same power, but your eye is far more sensitive to green, so it seems stronger. [Brandon Li] was thinking about how to best represent colors on computer screens and fell down the rabbit hole of what colors look like when arranged in a spectrum. Spoiler alert: almost all the images you see of the spectrum are incorrect in some way. The problem isn’t in our understanding of the physics, but more in the understanding of how humans perceive color.

Perception may start with physics, but it also extends to the biology of your eye and the psychology of your brain. What follows is a lot of math that finally winds up with the CIE 1931 color space diagram and the CIE 2012 system.

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Microfluidic Display Teaches The Basics

February 15, 2026 by 8 Comments

We’ve always been interested in fluidic logic and, based on [soiboi’s] videos, he is too. His latest shows how to use silicone and a vacuum to build a multiplexed dot matrix display. This is a fascinating look at how you design with air instead of electrons.

Just like a regular display, it isn’t efficient to control each element separately. Usually, it’s better to multiplex such that 16 “pixels” need only row and column air valves. Just as you might use transistors, the project uses “air transistors” to build logic gates.

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The Weird Propeller That Offers Improved Agility On The Water

February 6, 2026 by 48 Comments

When it comes to seaborne propulsion, one simple layout has largely dominated over all others. You pair some kind of engine with some kind of basic propeller at the back of the ship, and then you throw on a rudder to handle the steering. This lets you push the ship forward, left, and right, and stopping is just a matter of turning the engine off and waiting… or reversing thrust if you’re really eager to slow down.

This basic system works for a grand majority of vessels out on the water. However, there is a more advanced design that offers not only forward propulsion, but also steering, all in the one package. It may look strange, but the Voith Schneider propeller offers some interesting benefits to watercraft looking for an edge in maneuverability.

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Getting The VIC-20 To Speak Again

February 5, 2026 by 9 Comments

The Commodore Amiga was famous for its characteristic Say voice, with its robotic enunciation being somewhat emblematic of the 16-bit era. The Commodore VIC-20 had no such capability out of the box, but [Mike] was able to get one talking with a little bit of work.

The project centers around the Adventureland cartridge, created by Scott Adams (but not the one you’re thinking of). It was a simple game that was able to deliver speech with the aid of the Votrax Type and Talk speech synthesizer box. Those aren’t exactly easy to come by, so [Mike] set about creating a modern equivalent. The concept was simple enough. An Arduino would be used to act as a go between the VIC-20’s slow serial port operating at 300 bps and the Speakjet and TTS256 chips which both preferred to talk at 9600 bps. The audio output of the Speakjet is then passed to an LM386 op-amp, set up as an amplifier to drive a small speaker. The lashed-together TTS system basically just reads out the text from the Adventureland game in an incredibly robotic voice. It’s relatively hard to understand and has poor cadence, but it does work – in much the same way as the original Type and Talk setup would have back in the day!

Text to speech tools have come a long way since the 1980s, particularly when it comes to sounding more natural. Video after the break.

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Lego Typewriter Writes Plastic Letters

February 3, 2026 by 5 Comments

Some time ago, Lego released a beautiful (and somewhat pricey) typewriter set that was modeled after one used by company founder Ole Kirk Kristiansen. To the disappointment of some, it doesn’t actually work—you can’t really write a letter with it. [Koenkun Bricks] decided to rectify this with their own functional design.

Right away, we’ll state that this is not a traditional typewriter. There are no off-the-shelf Lego components with embossed letters on them, so it wasn’t possible to make Lego type bars that could leave an impression on paper with the use of an inked ribbon. Instead, [Koenkun Bricks] decided to build a design that was Lego all the way down, right to the letters themselves. The complicated keyboard-actuated mechanism picks out flat letter tiles and punches them on to a flat Lego plate, creating a plastic document instead of a paper one.

It’s not perfect in operation. It has some issues unique to its mode of operation. Namely, the round letter tiles sometimes rotate the wrong way as they’re feeding through the typewriter’s mechanisms, so you get sideways letters on your finished document. It looks kind of cool, though. Outside of that, sometimes the letter pusher doesn’t quite seat the letter tiles fully on the document plate.

Overall, though, it’s a highly functional and impressive build. We’ve seen some other great DIY typewriters before, too, like this 3D printed build. Video after the break.

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IPhone Becomes A Bluetooth Keyboard And Mouse

February 1, 2026 by 24 Comments

Sometimes you need to use a computer and you don’t have a spare keyboard and mouse on hand. [KoStard] figured an iPhone could serve as a passable replacement interface device. To that end, he built an adapter to let the phone act as a wireless keyboard and mouse on just about any modern machine.

To achieve this, [KoStard] grabbed an ESP32-S3 development board, and programmed it to act as a USB HID device to any machine attached over USB. It then listens out for Bluetooth LE communications from an iPhone equipped with the companion app. The app provides an on-screen keyboard on the iPhone that covers everything including special keys, symbols, and punctuation. You can also take advantage of the iPhone’s quality capacitive touchscreen, which emulates a nicely-responsive  trackpad, with two-finger taps used for right clicking and two-finger drags for scroll. Latency is nice and low courtesy of the direct Bluetooth LE connection.

It’s a nifty build that is particularly useful in oddball situations where you might want a keyboard and mouse. For example, [KoStard] notes it’s a great way to control a Smart TV without having to do ugly slow “typing” on an infrared remote. We’ve seen his work before, too—previously building an adapter to provide Bluetooth capability to any old USB keyboard. Video after the break.

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The Fancy Payment Cards Of Taiwan

January 28, 2026 by 25 Comments

If you’re an old-schooler, you might still go to the local bar and pay for a beer with cash. You could even try and pay with a cheque, though the pen-and-paper method has mostly fallen out of favor these days. But if you’re a little more modern, you might use a tap-to-pay feature on a credit or debit card.

In Taiwan, though, there’s another unique way to pay. The island nation has a whole ecosystem of bespoke payment cards, and you can even get one that looks like a floppy disk!

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