Peggyboard Will Have You Climbing The Walls Repeatedly

When you can’t climb actual rocks all the time, what do you do to train and keep sharp? You go to a rock-climbing gym, naturally. But what do you do when it’s 2020 and your rock-climbing gym has shuttered for the foreseeable? You build the best darn rock-climbing wall possible, and you outfit it with an LED for every hold and write an app that lets you plan your route and repeat it later.

This is essentially a DIY version of something called a Moonboard, which, aside from being expensive, was quickly going out of stock back in 2020. [Pegor] started the Peggyboard by building a climbing woody, which is a legendary home climbing wall built by a legendary climber about 20 years ago.

The Peggyboard is Raspberry Pi-powered and has a rather nice app going for it, which [Pegor] has kindly decided to open source.

On the initial screen, the user can select a route and assign the holds as either starting holds, foot holds, hand holds, or finishing holds, each with a different color LED. Another screen lets the user choose a previously-saved route, then apply it to the Peggyboard’s LEDs with the light bulb icon.

Don’t know where to get started building your own climbing wall? You can 3D print climbing holds, you know.

Bioadhesive Polymer Semiconductors For In-Vivo Sensors

The bioadhesive electrodes on a roll.
The bioadhesive electrodes on a roll.

What do you do when you want to stick an electrode or even an couple of sensors to an internal organ, such as a heart? Generally you’d use some kind of special adhesive, or sutures to ensure that the item remains firmly in place and doesn’t migrate to somewhere else within the chest cavity or among the intestines. According to a new study (press release) by Nan Li and colleagues in Science there may however be a more elegant method, using bioadhesive polymers.

The double-network copolymer is designed so that once put in the desired location it soaks up moisture and provides a dry interface for its bioadhesive properties. In addition, the resulting material is electrically conductive, with a measured charge-carrier mobility of ~1 square centimeter per volt per second.

Using thus manufactured electrodes were applied to both an isolated rat heart and in vivo rat muscles to measure electrical currents produced by each respective tissue type. The authors of the study envision that using this technology more complicated interfaces and sensors can be developed that would interface directly with organs and related. The claimed biocompatibility would also allow for such devices to be left in-situ for extended periods of time, which could be a boon for a wide range of medical conditions where continuous monitoring is a crucial element.

Life-Sized Rock’em Sock’em Robot Will Definitely Knock Your Block Off

He knocked his block off! That’s what [Zach] of Byte Sized Engineering is planning on saying when he completes this Rock’em Sock’em Robots replica. The twist? His replica is going to be life-sized. The original game involved two players, each controlling a robot that could punch and block with two lever-driven arms. [Zach] is looking to scale that up to human sized, but with a few interesting technical additions.

This build might be a bit large to be driven by a small child, so for the punching action [Zach] is using a four-bar linkage moved by a pneumatic cylinder. After some modelling, he decided on a 16mm bore and 100mm stroke cylinder that should provide a good, quick pneumatic action, but without putting so much force in that it destroys the whole thing. The aim is to knock his block off, not to permanently remove his block and take someone else’s  block with it. This first video details his first prototype of the arm and the first set of tests, with later videos hopefully getting more into the mechanism and technical details of the build. We’d also like to see  (hint, hint [Zach]) some of the files and code to follow up with.

Bonus fact: as older Brits may tell you, the game was marketed for some time there under the name “Raving Bonkers“, with the robots renamed as Basher Bonker and Biffer Bonker.  The name didn’t catch on, and they changed back to the Rock’em Sock’em robots name.  Ask someone in the UK these days if they want to play raving bonkers with your basher, and you will probably get your own block knocked off. Video below the break. Continue reading “Life-Sized Rock’em Sock’em Robot Will Definitely Knock Your Block Off”

2023 Halloween Hackfest: Treat Trough Of Terror Is Actually Pretty Cute

Even though it seems the worst of COVID has passed, October generally kicks off cold and flu season, so why not continue to pass out Halloween treats in a socially-distanced fashion?

That is, of course the idea behind [Gord Payne]’s Halloween Treat Trough of Terror. Lay a treat at the top of the trough and it will activate the LED strips that follow the treat down to the end, as well as some spooky sounds. The treat in question is detected by an SR-04 ultrasonic distance sensor connected to an Arduino Nano.

All in all this was a highly successful build as far as neighborhood entertainment value goes. Toddlers stared in awe at the blinkenlights, teenagers proclaimed it ‘sick’, and we can only assume that the adults were likely happy to see something aimed at kids that’s not scary.

[Gord] has a nice how-to if you want to build your own, and of course, the Arduino sketch is available. Be sure to check it out in action after the break.

Don’t have room to build a treat slide? Here’s a socially-distanced dispenser that lets them stomp a giant button.

Continue reading “2023 Halloween Hackfest: Treat Trough Of Terror Is Actually Pretty Cute”

Bus Sniffing The Model 5150 For Better Emulation

At the risk of stating the obvious, a PC is more than just its processor. And if you want to accurately emulate what’s going on inside the CPU, you’d do well to pay attention to the rest of the machine, as [GloriousCow] shows us by bus-sniffing the original IBM Model 5150.

A little background is perhaps in order. Earlier this year, [GloriousCow] revealed MartyPC, the cycle-accurate 8088 emulator written entirely in Rust. A cycle-accurate emulation of the original IBM PC is perhaps a bit overkill, unless of course you need to run something like Area 5150, a demo that stretches what’s possible with the original PC architecture but is notoriously finicky about what hardware it runs on.

Getting Area 5150 running on an emulator wasn’t enough for [GloriousCow], though, so a deep dive into exactly what’s happening on the bus of an original IBM Model 5150 was in order. After toying with and wisely dismissing several homebrew logic analyzer solutions, a DSLogic U3Pro32 logic analyzer was drafted into the project.

Fitting the probes for the 32-channel instrument could have been a problem except for the rarely populated socket for the 8087 floating-point coprocessor on the motherboard. A custom adapter gave access to most of the interesting lines, including address and data buses, while a few more signals, like the CGA sync lines, were tapped directly off the video card.

Capturing one second of operation yielded a whopping 1.48 GB CSV file, but a little massaging with Python trimmed the file considerably. That’s when the real fun began, strangely enough in Excel, which [GloriousCow] used as an ad hoc but quite effective visualization tool, thanks to the clever use of custom formatting. We especially like the column that shows low-to-high transitions as a square wave — going down the column, sure, but still really useful.

The whole thing is a powerful toolkit for exploring the action on the bus during the execution of Area 5150, only part of which [GloriousCow] has undertaken as yet. We’ll be eagerly awaiting the next steps on this one — maybe it’ll even help get the demo running as well as 8088MPH on a modded Book8088.

Review: LibrePCB Hits Version 1.0

Nearly three years ago at the start of 2020 and before the pandemic hit, we took a look at an up-and-coming player in the world of PCB design. LibrePCB is by no means as old as the more established players, but at the time it was joining the ranks of open-source EDA packages with its first early stable releases. It showed a lot of promise but was still a little rough around the edges back then, but in the years since it’s advanced to the extent that in September they released version 1.0. That’s a significant moment for any open source package, so it’s time to return and take another look. It’s a cross-platform package with builds available for Linux, Windows, MacOS and FreeBSD, of which I needed the Linux version. There are one or two options to choose from, I went for the appImage as probably the least trouble. Very quickly I was in a new EDA package, and I set out to make a simple Schmitt trigger oscillator as a test project. Continue reading “Review: LibrePCB Hits Version 1.0”

Metamaterial Enables Topological Pumping Of Elastic Surface Waves

Although it is generally assumed that surface elastic waves (vibrations) — such as those of earthquakes — will travel mostly unimpeded until their energy dissipates, there are ways to ‘steer’ this energy using metamaterials.

Time response of the topological surface wave transport.(A to C). The magnitude of total displacement field at 0.5 ms, 2.5 ms, and 4 ms, respectively. A 50-cycle tone burst signal centered at 41.88 kHz is simulated on the bottom supercell. (Wang et al., 2023)
Time response of the topological surface wave transport.
(A to C). The magnitude of total displacement field at 0.5 ms, 2.5 ms, and 4 ms, respectively. A 50-cycle tone burst signal centered at 41.88 kHz is simulated on the bottom supercell. (Wang et al., 2023)

A recent study by [Shaoyun Wang] and colleagues in Science Advances details how a carefully modelled grouping of columns creates what is termed a synthetic dimension. In their experimental setup, it is demonstrated how an applied wave is guided across the metamaterial, rather than spreading out the way which we would expect to see in conventional materials.

Interestingly, in the paper it is also demonstrated how the same technique can be used to create a wave-splitter that diverts the wave energy in two distinct directions. Due to the innate resistance of this type of structure to defects, manufacturing it is not too complicated.

In this experiment the metamaterials were milled out of a block of aluminium on a CNC mill, which makes it seem eminently realistic that it could be scaled up and translated to other applications. Conceivably annoyances like vibrations from road traffic and heavy machinery, all the way up to the destructive energies of earthquakes could one day be reduced, redirected or even extinguished using structures as demonstrated here.