Man playing custom zither made with a laser cutter.

Laser Cut Zither Instrument Kicks It Old World Style

Learning to play an instrument takes a certain level of dedication — and you can add another layer of dedication on top of that when it’s an instrument not found at your local Guitar Center. But it’s an entirely new level of dedication when someone crafts the instrument from scratch. If you’re looking for an example, check out this custom wooden zither [Nicolas Bras] built from laser cut parts.

The basic design of the instrument utilizes the sloted interlocking edges that are then glued together in lieu of traditional fasteners. Standard sized guitar tuning pegs and the accompanying steel guitar strings were then strung across two laser-cut bridges held in place by the string tension alone. The project began as way for [Nicolas] to learn the capabilities of his newly acquired laser cutter, but he himself is no amateur when it comes to constructing one-of-a-kind musical instruments. Just last year, he created a zither with bungee cords from the hardware store.

Zithers are German in origin, though some of the earliest zither-like instruments date back to 400 BCE China. The laser cut version [Nicolas] created had five strings to hammer on, though the type used in classical music arrangements typically contain upwards of thirty strings. The zither family of instruments may have given way to the electric guitars of today — it’s always neat to see new tech leveraged to embrace some old world charm.

For more on the art of DIY music production, check out this post on myriad of DIY musical instrument builds all played in concert.

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A white cargo van drives over a black asphalt road. An "x-ray" illustration shows the inductive coils inside the road as it drives over them.

Charging While Driving Now Possible In Michigan

Heavy vehicles like semi trucks pose a bigger challenge in electrifying the transportation fleet than smaller, more aerodynamic passenger cars. Michigan now has the first public in-road charging system in the United States to help alleviate this concern. [via Electrek]

Electreon, a company already active in Europe, won the contract to provide for the inductive coil-based charging system at the new Michigan Central Station research campus. Initial runs will be with a Ford E-Transit for testing, but there are plans to actually allow public use along the one mile (1.6 km) route in the near future.

Vehicles using the system need a special receiver, so we hope we’ll be seeing an open standard develop instead of having to have a different receiver for each road you drive on. This seems like it would be a more onerous swap than having to have three different toll road transponders. Unfortunately, the page about wireless standards on the Electreon website currently 404s, but CharIN, the standards body behind the Combined Charging Standard (CCS) did just launch a task force for wireless power delivery in September.

If you’re curious about other efforts at on-road charging, check out this slot car system in Sweden or another using pantographs.


An illustration of a powerplant, solar panel, and two wind turbines is in the bottom left across from an image of three cartoon people holding up a giant battery above their heads. Along the top of the image are the words, "Emergency Battery Network Toolkit." Below in a white bubble on the yellow background, it says, "How to share energy resources with your community in times of need." In the space between the people and the power plant, it says, "A Partnership of Shareable and People Power Battery Collective."

Sneakernet Power Transmission

Power outages in the face of natural disasters or more mundane grid failures can range from a mild inconvenience to a matter of life or death if you depend on electrical medical equipment. [Shareable] and [People Power Battery Collective] have partnered to develop a toolkit for communities looking to share power with each other in these situations.

Battery backup power isn’t exactly a new concept, so the real meat of this guide is how to build a network in your community so these relatively simple devices can be deployed effectively in the event of an emergency. We know that you can already handle your own backup power needs, but it pays to be a good neighbor, especially when those neighbors are deciding what to do when you’re releasing the factory-sealed smoke from your latest build on the community sidewalk.

For those who aren’t as technically-inclined as you, dear reader, there is also a handy Battery Basics (PDF) guide to help in selecting a battery backup solution. It is somewhat simplified, but it covers what most people would need to know. A note on fire safety regarding Li-ion batteries would probably be warranted in the Battery Basics document to balance the information on the risks of topping up lead-acid cells, but it otherwise seems pretty solid.

If you’re not quite ready to bug your neighbors, how about you build a backup battery first? How about repurposing an e-bike battery or this backup power solution for keeping a gas water heater working during a power outage?

Quick Negative Voltage For An Op Amp

It is a classic problem when designing with op amps: you need the output to go to zero, but — for most op amps — you can’t quite get down to the supply rail. If your power options are a positive voltage and ground, you can’t get down to zero without a special kind of op amp which might not meet your needs. The best thing to do is provide a negative supply to the chip. Don’t have one? [Peter Demchenko] can help. He uses a simple two-transistor multivibrator along with some diodes and capacitors to generate a minimal negative voltage for this purpose.

The circuit is simple and only produces a small negative voltage. He mentions that into a 910 ohm load, he sees about -0.3V. Not much, but enough to get that op amp down to zero with a reasonable load. Unlike other circuits he’s used in the past, this one is efficient. With a 5-volt input, it draws less than 1.5 mA.

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Disposable Vape Batteries Turned USB Power Bank

It’s another one of those fun quirks about our increasingly cyberpunk world — instead of cigarette butts littering our streets, you’re more likely to find disposable vaporizers that have run out of juice. Unfortunately, while the relatively harmless paper remnants of a cig would eventually just fall apart when exposed to the elements, these futuristic caltrops are not only potentially explosive thanks to their internal lithium-ion battery but aren’t going anywhere without some human intervention.

So do the environment and your parts bin a favor: pick them up and salvage their internal cells. As [N-Ender_3] shows with this build, it’s cheap and easy to turn the remnants of a few vapes into a useful USB power bank. In this case, the enclosure is 3D printed, which makes it particularly form-fitting, but you could just as easily pack the cells into something else if you’re not a fan of extruded plastic.

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Hacker Tactic: Internal ESD Diode Probing

Humans are walking high voltage generators, due to all the friction with our surroundings, wide variety of synthetic clothes, and the overall ever-present static charges. Our electronics are sensitive to electrostatic discharge (ESD), and often they’re sensitive in a way most infuriating – causing spurious errors and lockups. Is there a wacky error in your design that will repeat in the next batch, or did you just accidentally zap a GPIO? You wouldn’t know until you meticulously check the design, or maybe it’s possible for you to grab another board.

Thankfully, in modern-day Western climates and with modern tech, you are not likely to encounter ESD-caused problems, but they were way more prominent back in the day. For instance, older hackers will have stories of how FETs were more sensitive, and touching the gate pin mindlessly could kill the FET you’re working with. Now, we’ve fixed this problem, in large part because we have added ESD-protective diodes inside the active components most affected.

These diodes don’t just help against ESD – they’re a general safety measure for protecting IC and transistor pins, and they also might help avoid damaging IC pins if you mix. They also might lead to funny and unexpected results, like parts of your circuit powering when you don’t expect them to! However, there’s an awesome thing that not that many hackers know — they let you debug and repair your circuits in a way you might not have imagined.

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The Nintendo Switch CPU Exposed

Ever wonder what’s inside a Nintendo Switch? Well, the chip is an Nvidia Tegra X1. However, if you peel back a layer, there are four ARM CPU cores inside — specifically Cortex A57 cores, which take up about two square millimeters of space on the die. The whole cluster, including some cache memory, takes up just over 13 square millimeters. [ClamChowder] takes us inside the Cortex A57 inside the Nintendo Switch in a recent post.

Interestingly, the X1 also has four A53 cores, which are more power efficient, but according to the post, Nintendo doesn’t use them. The 4 GB of DRAM is LPDDR4 memory with a theoretical bandwidth of 25.6 GB/s.

The post details the out-of-order execution and branch prediction used to improve performance. We can’t help but marvel that in our lifetime, we’ve seen computers go from giant, expensive machines to the point where a game console has 8 CPU cores and advanced things like out-of-order execution. Still, [ClamChowder] makes the point that the Switch’s processor is anemic by today’s standards, and can’t even compare with an outdated desktop CPU.

Want to program the ARM in assembly language? We can help you get started. You can even do it on a breadboard, though the LPC1114 is a pretty far cry from what even the Switch is packing under the hood.