Day: December 22, 2024

Faster Integer Division With Floating Point

December 22, 2024 by 24 Comments

Multiplication on a common microcontroller is easy. But division is much more difficult. Even with hardware assistance, a 32-bit division on a modern 64-bit x86 CPU can run between 9 and 15 cycles. Doing array processing with SIMD (single instruction multiple data)  instructions like AVX or NEON often don’t offer division at all (although the RISC-V vector extensions do). However, many processors support floating point division. Does it make sense to use floating point division to replace simpler division? According to [Wojciech Mula] in a recent post, the answer is yes.

The plan is simple: cast the 8-bit numbers into 32-bit integers and then to floating point numbers. These can be divided in bulk via the SIMD instructions and then converted in reverse to the 8-bit result. You can find several code examples on GitHub.

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DIY Camera Slider Moves And Rotates For Slick Shots

December 22, 2024 by 14 Comments

Camera sliders are a popular project for makers—especially those who document their projects on video. They’re fun and accessible to build, and they can really create some beautiful shots. [Lechnology] set about to follow in this fine tradition and built a rather capable example of his own. Check it out in the video below.

The slider relies on V-slot rails, perhaps most familiar for their heavy use in modern 3D printers. The rails are paired with a 3D-printed camera carriage, which runs on smooth rubber rollers. A chunky stepper motor provides drive via a toothed belt. Trinamic motor controllers were chosen for their step interpolation feature, making the motion much smoother.

The slider doesn’t just move linearly, either. It can rotate the camera, too, since it has an additional motor in the carriage itself. In a nice retro touch, the wires for this motor are run with an old coiled telephone cable. It’s perfect for the job since it easily extends and retracts with the slider’s motion. Controlling everything is an Arduino, with speed and rotational modes set via a tiny screen and a rotary encoder control.

It’s a very complete build, and it performs well too. The video it produces is deliciously smooth. We’ve featured some other great camera sliders over the years, too. If you want to dig into Trinamic drivers, we can get you started.

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Hackaday Links: December 22, 2024

December 22, 2024 by 11 Comments

Early Monday morning, while many of us will be putting the finishing touches — or just beginning, ahem — on our Christmas preparations, solar scientists will hold their collective breath as they wait for word from the Parker Solar Probe’s record-setting passage through the sun’s atmosphere. The probe, which has been in a highly elliptical solar orbit since its 2018 launch, has been getting occasional gravitational nudges by close encounters with Venus. This has moved the perihelion ever closer to the sun’s surface, and on Monday morning it will make its closest approach yet, a mere 6.1 million kilometers from the roiling photosphere. That will put it inside the corona, the sun’s extremely energetic atmosphere, which we normally only see during total eclipses. Traveling at almost 700,000 kilometers per hour, it won’t be there very long, and it’ll be doing everything it needs to do autonomously since the high-energy plasma of the corona and the eight-light-minute distance makes remote control impossible. It’ll be a few days before communications are re-established and the data downloaded, which will make a nice present for the solar science community to unwrap.

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3D Printed Forklift Is A Cute Desk Toy

December 22, 2024 by 10 Comments

Many of us grew up with dreams of piloting a forklift one day. Sadly, most warehouses take a dim view of horseplay with these machines, so few of us get to live out those fantasies. Playing with this desk-sized RC model from [ProfessorBoots] is probably a safer way to get those kicks instead. You can check it out in the video below.

The 3D-printed body of the forklift is the first thing you see. It’s great quality, and it instantly puts you in mind of the real thing. The build is true to the dynamics of a real forklift, too, with proper rear steering. Inside, there’s a custom circuit board hosting an ESP32 that serves as the brain of the operation. Its onboard wireless hardware allows remote control of the forklift via a smartphone app, PS4 controller, or many other options. It controls the drive motors and steering servo, along with another motor driving a threaded rod to move the forks up and down. The whole thing is powered by two Fenix 16340 batteries—small lithium-ion cells that can be recharged with an integral micro USB port.

The project video is very thorough about the design and build. It’s worth watching just to understand the specifics of how forklifts actually raise their forks up and down. It’s good stuff.

This forklift is just the latest RC build from [ProfessorBoots]. He’s done great work in this space before, like this charming skid steer and incredibly complex crane.

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Optimizing Your Linux Shell Experience

December 22, 2024 by 33 Comments

Are you familiar with Huffman encoding? That’s where you pick shorter codes for more frequent letters. Morse code is the same way, in that the most-used letters are the shortest. [Matheus Richard] had the same idea for optimizing your workflow in the Linux shell. The idea is to measure what commands you use the most and make them shorter.

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Old 3D Printer Parts Repurposed Into DIY Camera Slider

December 22, 2024 by 7 Comments

What do you do with an old 3D printer? They’re full of interesting components, after all, from switches and motors to lovely smooth rails. [Mukesh Sankhla] had a great idea—why not repurpose the components into a motorized camera slider?

The heart of the slider is the 4020 V-slot aluminum profile. It’s upon this that the camera carriage rides, running on rubber rollers to keep things smooth. A stepper motor and belt are then used to move the slider at a constant speed up or down the rail while the camera gets the necessary shot. The build relies almost entirely on salvaged components, save for an ESP32, OLED screen, and a few buttons to act as the control interface. There are also the TMC2208 stepper motor drivers, of course, but they came from the salvaged Ender 3 unit as well.

This is a classic project. Many old 3D printers have pretty much the perfect set of parts to build a camera slider, making this build a no-brainer. Indeed, others have tread the same path. There are plenty of other potential uses around the lab or for soldering.

Meanwhile, the proof is in the pudding. Scope the slider’s performance in the video below.

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Dog Plays Chess On ESP32

December 22, 2024 by 10 Comments

The ESP32 is s remarkably powerful microcontroller, where its dual-core processor and relatively high clock speed can do some impressive work. But getting this microcontroller designed for embedded systems to do tasks that would generally be given to a much more powerful PC-type computer takes a little bit more willpower. Inspired by his dog, [Folkert] decided to program an ESP32 to play chess, a famously challenging task for computer scientists in the past. He calls this ESP32 chess system Dog.

One of the other major limitations of this platform for a task like this is memory. The ESP32 [Folkert] is using only has 320 kB of RAM, so things like the transposition table have to fit in even less space than that. With modern desktop computers often having 32 or 64 GB, this is a fairly significant challenge, especially for a memory-intensive task like a chess engine. But with the engine running on the microcontroller it’s ready to play, either in text mode or with something that can use the Universal Chess Interface (UCI). A set of LEDs on the board lets the user know what’s going on while gameplay is taking place.

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