Day: March 20, 2025

A Modern Take On The Etch A Sketch

March 20, 2025 by 4 Comments

The Etch A Sketch is a classic children’s toy resembling a picture frame where artwork can be made by turning two knobs attached to a stylus inside the frame. The stylus scrapes off an aluminum powder, creating the image which can then be erased by turning the frame upside down and shaking it, adding the powder back to the display. It’s completely offline and requires no batteries, but in our modern world those two things seem to be more requirements than when the Etch A Sketch was first produced in the 1960s. Enter the Tilt-A-Sketch, a modern version of the classic toy.

Rather than use aluminum powder for the display, the Tilt A Sketch replaces it with an LED matrix and removes the stylus completely. There are no knobs on this device to control the path of the LED either; a inertial measurement unit is able to sense the direction that the toy is tilted while a microcontroller uses that input to light up a series of LEDs corresponding to the direction of tilt. There are a few buttons on the side of the device as well which allow the colors displayed by the LEDs to change, and similar to the original toy the display can be reset by shaking.

The Tilt-A-Sketch was built by [devitoal] as part of an art display which allows the visitors to create their own art. Housed in a laser-cut wooden enclosure the toy does a faithful job of recreating the original. Perhaps unsurprisingly, the Etch A Sketch is a popular platform for various projects that we’ve seen before including original toys modified with robotics to create the artwork and electronic recreations that use LED displays instead in a way similar to this project.

Continue reading “A Modern Take On The Etch A Sketch” →

Solar Power, Logically

March 20, 2025 by 44 Comments

We’ve all seen the ads. Some offer “free” solar panels. Others promise nearly free energy if you just purchase a solar — well, solar system doesn’t sound right — maybe… solar energy setup. Many of these plans are dubious at best. You pay for someone to mount solar panels on your house and then pay them for the electricity they generate at — presumably — a lower cost than your usual source of electricity. But what about just doing your own set up? Is it worth it? We can’t answer that, but [Brian Potter] can help you answer it for yourself.

In a recent post, he talks about the rise of solar power and how it is becoming a large part of the power generation landscape. Interestingly, he presents graphs of things like the cost per watt of solar panels adjusted for 2023 dollars. In 1975, a watt cost over $100. These days it is about $0.30. So the price isn’t what slows solar adoption.

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Backyard Rope Tow From Spare Parts

March 20, 2025 by 7 Comments

A few years ago, [Jeremy Makes Things] built a rope tow in his back yard so his son could ski after school. Since the lifts at the local hill closed shortly after schools let out, this was the only practical way for his son to get a few laps in during the week. It’s cobbled together from things that [Jeremy] had around the house, and since the original build it’s sat outside for a few years without much use. There’s been a lot more snow where he lives this year though, so it’s time for a rebuild.

The power source for the rope tow is an old gas-powered snowblower motor, with a set of rollers and pulleys for the rope made out of the back end of a razor scooter. Some polyurethane was poured around the old wheel hub so that the rope would have something to grip onto. The motor needed some sprucing up as well, from carburetor adjustment, fuel tank repairs, and some other pieces of maintenance before it could run again. With that out of the way it could be hoisted back up a tree at the top of the hill and connected to the long rope.

This isn’t the first time [Jeremy] has had to perform major maintenance on this machine either. Three years ago it needed plenty of work especially around the polyurethane wheel where [Jeremy] also had to machine a new wheel bearing in addition to all the other work that had to go into repairing it that time. From the looks of things though it’s a big hit with his son who zips right back up the hill after each ski run. Getting to the tops of ski runs with minimal effort has been a challenge of skiers and snowboarders alike for as long as the sport has been around, and we’ve seen all kinds of unique solutions to that problem over the years.

Laser Harp Sets The Tone

March 20, 2025 by 12 Comments

In many ways, living here in the future is quite exiting. We have access to the world’s information instantaneously and can get plenty of exciting tools and hardware delivered to our homes in ways that people in the past with only a Sears catalog could only dream of. Lasers are of course among the exciting hardware available, which can be purchased with extremely high power levels. Provided the proper safety precautions are taken, that can lead to some interesting builds like this laser harp which uses a 3W laser for its strings.

[Cybercraftics]’ musical instrument is using a single laser to generate seven harp strings, using a fast stepper motor to rotate a mirror to precise locations, generating the effect via persistence of vision. Although he originally planned to use one Arduino for this project, the precise timing needed to keep the strings in the right place was getting corrupted by adding MIDI and the other musical parts to the project, so he split those out to a second Arduino.

Although his first prototype worked, he did have to experiment with the sensors used to detect his hand position on the instrument quite a bit before getting good results. This is where the higher power laser came into play, as the lower-powered ones weren’t quite bright enough. He also uses a pair of white gloves which help illuminate a blocked laser. With most of the issues ironed out, [Cybercraftics] notes that there’s room for improvement but still has a working instrument that seems like a blast to play. If you’re still stuck in the past without easy access to lasers, though, it’s worth noting that there are plenty of other ways to build futuristic instruments as well.

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Three SPI Busses Are One Too Many On This Cheap Yellow Display

March 20, 2025 by 13 Comments

The Cheap Yellow Display may not be the fastest of ESP32 boards with its older model chip and 4 MB of memory, but its low price and useful array of on-board peripherals has made it something of a hit in our community. Getting the most out of the hardware still presents some pitfalls though, as [Mark Stevens] found out when using one for an environmental data logger. The problem was that display, touch sensor, and SD card had different SPI busses, of which the software would only recognise two. His solution involves a simple hardware mod, which may benefit many others doing similar work.

It’s simple enough, put the LCD and SD card on the same bus, retaining their individual chip select lines. There’s a track to be cut and a bit of wiring to be done, but nothing that should tax most readers too much. We’re pleased to see more work being done with this board, as it remains a promising platform, and any further advancements for it are a good thing. If you’re interested in giving it a go, then we’ve got some inspiration for you.

Linux Fu: A Warp Speed Prompt

March 20, 2025 by 22 Comments

If you spend a lot of time at the command line, you probably have either a very basic prompt or a complex, information-dense prompt. If you are in the former camp, or you just want to improve your shell prompt, have a look at Starship. It works on the most common shells on most operating systems, so you can use it everywhere you go, within reason. It has the advantage of being fast and you can also customize it all that you want.

What Does It Look Like?

It is hard to explain exactly what the Starship prompt looks like. First, you can customize it almost infinitely, so there’s that. Second, it adapts depending on where you are. So, for example, in a git-controlled directory, you get info about the git status unless you’ve turned that off. If you are in an ssh session, you’ll see different info than if you are logged in locally.

However, here’s a little animation from their site that will give you an idea of what you might expect: Continue reading “Linux Fu: A Warp Speed Prompt” →

Chemistry Meets Mechatronics In This Engaging Art Piece

March 20, 2025 by 4 Comments

There’s a classic grade school science experiment that involves extracting juice from red cabbage leaves and using it as a pH indicator. It relies on anthocyanins, pigmented compounds that give the cabbage its vibrant color but can change depending on the acidity of the environment they’re in, from pink in acidic conditions to green at higher pH. And anthocyanins are exactly what power this unusual kinetic art piece.

Even before it goes into action, [Nathalie Gebert]’s Anthofluid is pretty cool to look at. The “canvas” of the piece is a thin chamber formed by plexiglass sheets, one of which is perforated by an array of electrodes. A quartet of peristaltic pumps fills the chamber with a solution of red cabbage juice from a large reservoir, itself a mesmerizing process as the purple fluid meanders between the walls of the chamber and snakes around and between the electrodes. Once the chamber is full, an X-Y gantry behind the rear wall moves to a random set of electrodes, deploying a pair of conductors to complete the circuit. When a current is applied, tendrils of green and red appear, not by a pH change but rather by the oxidation and reduction reactions occurring at the positive and negative electrodes. The colors gently waft up through the pale purple solution before fading away into nothingness. Check out the video below for the very cool results.

We find Anthofluid terribly creative, especially in the use of such an unusual medium as red cabbage juice. We also appreciate the collision of chemistry, electricity, and mechatronics to make a piece of art that’s so kinetic but also so relaxing at the same time. It’s the same feeling that [Nathalie]’s previous art piece gave us as it created images on screens of moving thread. Continue reading “Chemistry Meets Mechatronics In This Engaging Art Piece” →