Misc Hacks

4028 Articles

Cheating A Pedometer The Easy Way

November 20, 2021 by 9 Comments

These days, pedometers are integrated into just about every smartwatch on the market, and some of the dumber ones too. Tracking step counts has become a global pastime, and at times, a competitive one. However, any such competition can easily be gamed, as demonstrated by [Luc Volders].

Generally, all it takes to fool a basic pedometer is a gentle rhythmic jiggling motion of some sort. Cheaper devices will even register steps with little more than vague shaking.

[Luc] exploited this with basic machinery. A servo’s output shaft is fitted with a 3D printed cylinder, sized to allow a smartwatch to be attached as if to a wrist. Then, a Raspberry Pi Pico simply rocks the servo back and forth at regular intervals, and the watch begins counting these ersatz steps. Looking at the project as a whole, we’re betting [Luc] took some inspiration from old-fashioned automatic watch winders.

It’s hard to envision an important application for this technology. However, if one is in a friendly competition with friends who don’t scrutinize the results too closely, this would be an easy way to win.

Alternatively, consider building a pedometer to track your hamster’s exercise regime. If you’ve got your own exercise hacks on the go, drop us a line!

Light projected through prisms on to laser-cut letters submerged in water.

YOU Are A Projection Of Your Influences

November 18, 2021 by 5 Comments

Who are you? No, who are you really? You’re an amalgamation of influences from your family, your friends, the media, and the parasocial relationships you have with fictional characters. It’s okay; we all are. It can’t be helped that there’s a lot of it about.

[Kim Pimmel]’s YOU examines this question of identity in the form of  projected typography. YOU are solidly laser-cut at birth, but then come the influences — the water of everyday life that surrounds you, the lights that mask your dread or lay you bare, and the prisms of circumstance that twist the light into brilliant patterns that burn memories into your brain.

In this case, the light comes from a hacked camping headlamp that was past its prime. [Kim] laser-cut the letters from acrylic and submerged them in water, which can be manipulated to enhance the effect and mimic the turmoil of life. For added effect, [Kim] held prisms in the light’s path to refract it and cause the patterns to dance. Be sure to check it out after the break, and don’t forget to turn on the sound so you can hear [Kim]’s original composition.

Want to see more trippy typography? Check out this vector art that started as Perlin noise.

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A nixie tube next to a screenshot of a to-do list

Nixie Tube Indicator Tells You How Many Tasks You’ve Got Left To Do

November 17, 2021 by 10 Comments

For busy people, keeping track of all the tasks on your to-do list can be a daunting task in itself. Luckily there’s software to help you keep organized, but it’s always nice to have a physical artifact as well. Inspired by some beautiful nixie clock designs, [Bertrand Fan] decided to build a nixie indicator that tells him how many open items are on his to-do list, giving a shot of instant gratification as it counts down with each finished task.

The task-management part of this project is a on-line tool called Todoist. This program comes with a useful Web API that allows you to connect it your own software projects and exchange data. [Bert] wrote some code to extract the number of outstanding tasks from his to-do list and send it to an ESP8266 D1 Mini that drives the nixie tube. Mindful of the security implications of letting such a device connect directly to the internet, he set up a Mac Mini to act as a gateway, connecting to the ESP8266 through WiFi and to the Todoist servers through a VPN.

The little ESP board is sitting in a 3D-printed case, together with the nixie driver circuits and a socket to hold the tube. A ceramic tile glued to the front gives it a bit more of a sturdy, luxury feel to match the shiny glass and metal display device. The limitations of the nixie tube restrict the number of tasks indicated to nine, but we imagine this might actually be useful to help prevent [Bert] from overloading himself with too many tasks. After all, what’s the point of having this device if you can’t reach that satisfying “zero” at the end of the day?

Although nowadays nixie tubes are mostly associated with fancy clocks, we’ve seen them used in a variety of other uses, such as keeping track of 3D-printer filament, adding a display to a 1940s radio, or simply displaying nothing useful at all.

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Quick And (Not Very) Dirty Negative Voltage Supply

November 16, 2021 by 11 Comments

There comes a time in every hardware hacker’s career during which they first realize they need a negative voltage rail in their project. There also comes a time, usually ~10ms after realizing this, when they reach for the Art of Electronics to try and figure out how the heck to actually introduce subzero voltages into their design. As it turns out, there are a ton of ways to get the job done, from expensive power supplies to fancy regulators you can design, but if you’re lazy (like I am) you might just want a simple, nearly drop-in solution.

[Filip Piorski] has got you covered there. In a recent video, he demonstrates how to turn a “China Special” $1 buck converter from Ebay into a boost-buck converter, capable of acting as a negative voltage supply. He realized that by swapping around the inputs and outputs of the regulator you can essentially invert the potential produced. There are a few caveats, of course, including high start-up current and limited max. voltages, but he manages to circumvent some of them with a little clever rewiring and a bit of bodge work.

Of course, if you have strict power supply requirements you probably want to shell out the cash for a professionally-built one, or design one yourself that meets your exact needs. For the majority of us, a quick and easy solution like this will get the job done and allow us to focus on other aspects of the design without having to spend too much time worrying about the power supply. Of course, if power electronics design is your thing, we’ve got you covered there, too.

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Circuit Sculpture Lamp Is A Colorful Cube Companion

November 15, 2021 by 10 Comments

Circuit sculpture is engineering and art all at play together. One must combine the functional with the aesthetically appealing. [EdwardA61] did just that with this enchanting lamp build.

Like many other circuit sculptures, the build relies on the aesthetic qualities of brass, though [EdwardA61] notes that copper wire can be used as well. Four WS2812B LEDs, in their bare PCB-mount form, are soldered into a circuit using the brass to carry the power and data signals as needed.

A Seeduino Xiao microcontroller is responsible for controlling the show, though relies on a typical PCB rather than a circuit sculpture in and of itself. It does provide for easy powering and programming however, with the benefit of its USB-C connector.

It’s a simple skeleton design, as so many circuit sculptures are, but it’s a form that we’ve come to love and appreciate. [EdwardA61] did a great job of photographing the build, too, showing how the colors on each LED interplay with each other as they’re cast on the table.

It’s a lamp we’d love to build ourselves, and we hope that [EdwardA61] follows through on plans to cast a similar design in clear resin, as well. If you’ve built your own artistically electrical sculptures, be sure to let us know!

Mechanical 7-segment display

A One-Servo Mechanical Seven-Segment Display

November 13, 2021 by 21 Comments

The seven-segment display may be a bit prosaic after all these years, but that doesn’t mean there aren’t ways to spice it up. Coming up with a mechanical version of the typical photon-based display is a popular project, of which we’ve seen plenty of examples over the years. But this seven-segment display is quite a mechanical treat, and a unique way to flip through the digits.

With most mechanical displays, we’re used to seeing the state of each segment changed with some kind of actuator, like a solenoid or servo. [Shinsaku Hiura] decided on a sleeker design using a 3D-printed barrel carrying one cam for each segment. Each hinged segment is attached to an arm that acts as a follower, riding on its cam and flipping on or off in a set pattern. Which digit is displayed depends on the position of the barrel, which is controlled with a single servo and a pair of gears. It trades mechanical complexity for electrical simplicity and overall elegance, and as you can see from the video below, it’s pretty snappy.

We think the best part of this build is figuring out the shape of the cams. We wonder how they compare to the cam profiles in [Greg Zumwalt]’s mechanical display; it uses two separate discs with grooves, but the principle is pretty much the same.

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A Guide To Designing A Custom RC Controller

November 12, 2021 by 5 Comments

These days, there are tons of RC controllers out there of all shapes and sizes. However, if you want to build something with just the right amount of buttons and sticks for your application, you might want to design something yourself. That’s precisely what [Sebastian] did. 

The project actually began some time ago, with [Sebastian] sharing his process for building a custom ergonomic enclosure through the use of clay and photogrammetry, which we’ve covered before.

Inside that shapely housing, the build relies on a STM32 microcontroller, hooked up to a series of potentiometers, buttons, and a thumbstick (more potentiometers). A NRF24L01 module is used to handle the radio transmission side of things.

Overall, [Sebastian] has produced a great guide to designing a custom RC controller from the ground up, rather than simply instructing one how to replicate his own build. Armed with these skills, any maker should be able to whip up their own entirely bespoke controllers. Video after the break.

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