Wiring Harness? That’s A Wrap!

[Mr Innovative] likes to keep his wire harnesses tidy, but it is a pain to neatly wrap cables. So, he automated the process using a combination of milled acrylic and 3D printing. We hope the design files will be up on his website soon, although the mechanism is similar to another wrapping machine he made a few years ago. However, it can still be a source of inspiration if you want to do a unique take on it.

To use the machine, you feed the wires through the center hole and mount tape on the spool. A motor spins the spool and you only need to slowly advance the tool to get a nice close wrap. Naturally, you can wrap tape around wires by hand, so this is a bit of a luxury item. However, we could see modifying it to move the cable through at a constant rate with another motor, which might do a better job than you can do by hand.

We couldn’t help but wonder if you could start with a ping pong paddle instead of cutting the frame out of acrylic.

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TMS 1000 Microcontroller - By Antonio Martí Campoy - Own work, CC BY-SA 4.0

The Early History Of The Microcontroller: It Came From Texas

Ti’s presentation of the rapid integration of calculator chips.
Ti’s presentation of the rapid integration of calculator chips.

Although for most generations alive today the era of microcontrollers (MCU) feels like it starts somewhere with the Intel 8051 and AVR MCUs, the history of these self-contained computing marvels that are now found just about anywhere begins long before those were even conceptualized. In a recent article titled Tiny Computers From Texas, [Babbage] goes through this early history of what would ultimately become such an integral part of daily life.

An MCU is defined as a small, self-contained computer, which requires few to no external components to function. This contrasted with the more traditional MPUs, or microprocessor units, where a computer was assembled out of one or more MPUs, I/O chips, memory SRAM and so on. It’s perhaps little surprise that the drive towards MCUs was the result of primarily the calculator market, where competing firms were trying to upstage each other with higher levels of integration into as few chips as possible, while driving down costs and power usage.

Ultimately, the Texas Instruments TMS 1000 was the first true MCU that got produced in large volumes after its release in 1974. Moving beyond calculators, the TMS 1000 found its way into toys, including the Speak & Spell – which uses another Ti chip (TMS 5100) for the voice synthesis – so that today any toy can be interactive in exciting and often noisy ways.

Back in 2020 we took our own affectionate look at this chip.

All I Want For Mr. Christmas Is Some New Music

It’s true — you really can find anything (except maybe LEGO) in thrift stores. When [thecowgoesmoo] picked up a Mr. Christmas Symphonium music box one day, they knew they wanted to make it play more than just the standard Christmas and classical fare that ships with the thing.

So they did what any self-respecting hacker would do, and they wrote a MATLAB script that generates new disk silhouette images that they then cut from cardboard with a laser cutter. They also used various other materials like a disposable cutting mat. Really, whatever is lying around that’s stiff enough and able to be cut should work. You know you want to hear Van Halen’s “Jump” coming from a tinkling music box, don’t you? Be sure to check out the video demonstration after the break.

If you don’t want to wait around until a Mr. Christmas lands in your lap, why not make your own hand-cranked music box and accompanying scores?

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In Praise Of Old Meters

We are spoiled with multimeters today. Even the cheapest meter you will get these days is almost surely digital with a tremendous input impedance. But a few decades ago, meters were almost always analog affairs. To make a precise measurement, you needed a mirror under the meter to ensure you read the needle correctly. Moreover, a common meter wouldn’t have that high of an input impedance. If you spent more, you could get a VTVM and, later, one that used FETs to provide high input impedance. [Peter AA2VG] just picked up a vintage Micronta FET volt-ohm meter to join some of the other new and old meters in his shack. You can check it out in the video below.

[Peter] already has a Simpson and a more modern Fluke meter. The Simpson, however, doesn’t have a tube or FET amplifier. The Fluke is nice, but there is something about the needle on an analog meter. If you aren’t old enough to remember, the Micronta brand was a Radio Shack label.

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A Homebrew GPS Correction System For DIY Land Surveying

For those of you rushing to the comment section after reading the title to tell [Ben Dauphinee] that his DIY land surveying efforts are for naught because only a licensed surveyor can create a legally binding property description, relax — he already knows. But what he learned about centimeter-resolution GPS is pretty interesting, especially for owners of large rural properties like him.

[Ben]’s mapping needs are less rigorous than an official survey; he just wants to get the locations of features like streams and wood lines, and to get topographic elevations so that he has a general “lay of the land” for planning purposes. He originally engaged a surveyor for that job, but after shelling out $4,600 to locate a single property line, he decided to see what else could be done. Luckily, real-time kinematics, or RTK, holds the key. RTK uses a fixed GPS station to provide correction signals to a mobile receiver, called a rover. If the fixed station’s position is referenced to some monument of known position, the rover’s position can be placed on a map to within a couple of centimeters.

To build his own RTK system, [Ben] used some modules from SparkFun. The fixed station has an RTK breakout board and a multi-band GNSS antenna to receive positioning data, along with a Raspberry Pi to run the RTK server. An old iPhone with a prepaid SIM provides backhaul to connect to the network that provides correction data. [Ben]’s rover setup also came mainly from SparkFun, with an RTK Facet receiver mounted on a photographer’s monopod. Once everything was set up and properly calibrated, he was able to walk his property with the rover and measure locations to within 4 centimeters.

This was not an inexpensive endeavor — all told, [Ben] spent about $2,000 on the setup. That’s a lot, especially on top of what he already paid for the legal survey, but still a fraction of what it would have cost to have a surveyor do it, or to buy actual surveyor’s equipment. The post has a ton of detail that’s worth reading for anyone interested in the process of mapping and GPS augmentation.

Hackaday Podcast Episode 252: X1Plus Hacks Bambu, Scotto Builds A Katana Keyboard, And Bass Puts Out Fire

This week, Editor-in-Chief Elliot Williams and Kristina Panos met up to discuss the best hacks of the previous week. It’s CES time once again in Las Vegas, and you know what that means — some wacky technologies like this AI pet door that rejects dead mice.

Then it’s on to What’s That Sound, which Kristina managed to nail for once. Can you get it? Can you figure it out? Can you guess what’s making that sound this week? If you can, and your number comes up, you get a special Hackaday Podcast t-shirt.

But then it’s on to the hacks, beginning with a new keyboard from [Joe Scotto] and an exploration of all you can do with an LED strip, like 1D fireworks and roller coasters without any moving parts. From there, we marvel at the ability of sound waves to extinguish flames, and the tech behind life as a quadriplegic. Finally, we examine not one, but two of Jenny List’s finely-crafted rants, one about web browsers, and the other about the responsible use of new technology.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download and savor at your leisure.

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The Simple Tech Behind Hidden Camera Detectors

If you’ve ever been concerned about privacy in a rental space or hotel room, you might have considered trying one of the many “spy camera detectors” sold online. In the video after break [Big Clive], tears one down and gives us  an in-depth look at how these gadgets actually work, and their limitations.

Most detector follow the same basic design: a ring of LEDs through which the user inspects a room, looking for reflections indicating a potential hidden camera. Although this device can help spot a camera, it’s not entirely foolproof. The work best when you’re close to the center of a camera’s field of view, and some other objects, like large LEDs can produce similar reflections

The model examined in this video takes things one step further by adding a disc of dichroic glass. Coated with a metallization layer close to the wavelength of the LEDs, it effectively acts a bandpass filter, reducing reflections from other light sources. [Big Clive] also does his customary reverse-engineering of the circuit, which is just a simple flasher powered by USB-C.

[Big Clive]’s teardowns are always an educational experience, like we’ve seen in his videos on LED bulb circuits and a fake CO2 sensor.

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