An LCD, Touch Sensor, USB-C, And A Microcontroller For A Buck

December 21, 2024 by Lewin Day 16 Comments

[CNLohr] has been tinkering with some fun parts of late. He’d found out that ordinary LCD screens could be used as simple touch sensors, and he had to try it for himself. He ended up building a little doohickey that combined USB C, an LCD display, and a touch interface, all for under a buck. You can check out the video below.

The key to this build was the CH32V003 CPU. It’s a RISC-V microcontroller that runs at a healthy 48 MHz, and it costs just 10 cents in reasonable quantities. A PCB etched to mate with a USB C cable eliminates the need for a connector.

[CNLohr] then gave the board a three-digit 7-segment LCD display from Aliexpress, which can be had for around 21 cents if you buy 100 or more. He then figured out how to drive the LCDs with a nifty trick that let the microcontroller use the display as a crude touch sensor. All in all, the total bill of materials for one of these things comes out somewhere under a dollar in quantity.

It’s mostly a random assemblage of tech glued together for a demo, but it’s a fun project. It’s worth checking out even if it’s just to learn how to create an integral USB C port on your own PCBs. The way it’s achieved with the etched contacts and milled-out tabs is pure elegance. Files are on Github for the curious.

We’ve featured a ton of [CNLohr’s] work over the years; the clear keytar was a glowing highlight, as were his early discoveries in the depths of the ESP8266.

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Building A Custom Swiss Army Knife

December 21, 2024 by Lewin Day 14 Comments

The Swiss Army knife is the most well-known multitool, combining a bunch of functionality into a compact package. [Jeff Gough] decided to build a custom example featuring a selection of his favorite tools.

He documents the build in a video series on YouTube (see below). [Jeff] decided to take on the project as a gift for his mother after she’d mentioned she’d wanted a Swiss Army-style knife with a horse’s hoof tool and finished in the classic shade of British Racing Green.

[Jeff] starts by disassembling an existing knife, taking care not to damage it in the process. He then makes and installs multiple custom tools, including the aforementioned horse hoof tool and a RADAR/NKS key for opening disabled toilets in the UK. He even crafts a bespoke Philips head screwdriver, too. Finally, he assembles everything back together and gives the build a beautiful green finish.

A Swiss Army knife can be a neat gift, but it’s even nicer when it’s got a personal touch like this one. We’ve featured some other nifty multitools before, too. Not all Swiss Army knives actually contain a, you know, knife. No kidding.

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3D Printing A Big LEGO Christmas Tree

December 20, 2024 by Lewin Day 8 Comments

LEGO make lots of neat floral arrangements these days, and even little Christmas trees, too. While they’re fun to build out of tiny little blocks, they’re a little small for use as your main Christmas tree. Sadly, a bigger version simply doesn’t exist in the LEGO catalog, so if that’s your desire, you’ll have to build your own—as [Ruth] and [Ellis] did!

The concept behind the build is as you’d expect. The duo effectively just 3D printed giant versions of LEGO pieces, with which they then assembled a large Christmas tree. It sounds very straightforward, but scaling an existing LEGO design up by six times tends to come with some complications. A tactical decision was made early on to ease proceedings—the original LEGO tree had a large brown base that would take lots of printing. This was eliminated in the hopes that it would speed the build significantly. The long plastic shafts that supported the original design were also replaced with steel shafts since printing them would have been incredibly difficult to do well.

The rest of the video demonstrates the huge amount of work that went into actually 3D printing and assembling this thing. It’s pretty great to watch, and you’ll learn a lot along the way.

We’ve seen other creators try similar projects, where they 3D print their own building blocks from scratch. It normally turns out much harder than expected! No surprise when you think about all the engineering that went into perfecting LEGO all those years ago.

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Making A Mechanical Watch From Scratch Is Fine Work

December 20, 2024 by Lewin Day 7 Comments

There are plenty of hard jobs out there, like founding your country’s nuclear program, or changing the timing chain on a BMW diesel. Making your own mechanical watch from scratch falls under that umbrella, too. And yet, [John Raffaelli] did just that, and prevailed!

Only a handful of components were purchased—[John] grabbed jewels, sapphire crystals, the strap, and the hairspring and mainspring off the shelf. Everything else, he made himself, using a fine touch, a sharp eye, and some deft work on his machine tools. If you’ve never worked at this scale before, it’s astounding to see—[John] steps through how he produced tiny pinions and balance wheels that exist at sub-fingertip scale. Even just assembling something this tiny would be a challenge, but [John] was able to craft it all from scratch and put it together into a functioning timepiece when he was done.

The final piece doesn’t just look great—we’re told it keeps good time as well. People like [John] don’t come along every day, though we do have one similar story in our deep archives from well over a decade ago. If you’re cooking up your own bespoke time pieces in your home workshop, don’t hesitate to drop your story on the tipsline!

Building A Diet Coke Button

December 20, 2024 by Lewin Day 53 Comments

[mars91] had an interesting problem to solve—his girlfriend often requested Diet Coke, but yelling for one across the apartment was frustrating and impractical. A dedicated Diet Coke button seemed like the perfect solution, so that’s precisely what he built.

The Diet Coke Button is a relatively simple device. A small silver push-button activates an Adafruit Feather M0 to send out a signal via its RFM95 LoRa radio. That signal is picked up by the receiver device, which runs on an ESP32. It’s got an RFM95 LoRa module, which receives signals from the button and sounds an alarm to indicate the request for a Diet Coke. The ESP32 also hosts a basic website which allows Diet Coke requests to be submitted via the web, as well as general submissions of a textual nature. The latter are displayed on a small OLED display. If you’re feeling bold, you can even set up the ESP32 to be accessible from the outside Internet, with [mars91] explaining how to do so using a Cloudflare tunnel for your own protection.

The only problem is that delivering the Diet Coke is still something you have to do by hand. Perhaps a future upgrade would involve some kind of small apartment-spanning railway for the delivery of ice-cold cans to designated stations.

It’s a unique project, and one that recalls us of an interesting talk about a different type of call button.

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Embossing Leather With A Pipe Bender And 3D Printed Tooling

December 20, 2024 by Lewin Day 12 Comments

Embossed leather belts can be deliciously stylish. However, the tooling for making these fashionable items is not always easy to come by, and it rarely comes cheap. What do we do when a tool is expensive and obscure? We 3D print our own, as [Myth Impressions] demonstrates.

The build is based around a Harbor Freight pipe bender. However, instead of the usual metal tooling, it’s been refitted with a printed embossing ring specifically designed for imprinting leather. The tool features raised ridges in an attractive pattern, and the pipe bender merely serves as a straightforward device for rolling the plastic tooling over a leather belt blank. Once cranked through the machine, the leather belt comes out embossed with a beautiful design.

It’s a neat project, and the 3D printed tooling works surprisingly well. The key is that leather is relatively soft, so it’s possible to use plastic tools quite effectively. With that said, you can even form steel with printed tooling if you use the right techniques.

We’ve seen some other neat leatherworking hacks before, like this nicely-modified Singer sewing machine.

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Subchannel Stations: The Radio Broadcasts You Didn’t Know Were There

December 20, 2024 by Lewin Day 31 Comments

Analog radio broadcasts are pretty simple, right? Tune into a given frequency on the AM or FM bands, and what you hear is what you get. Or at least, that used to be the way, before smart engineers started figuring out all kinds of sneaky ways for extra signals to hop on to mainstream broadcasts.

Subcarrier radio once felt like the secret backchannel of the airwaves. Long before Wi-Fi, streaming, and digital multiplexing, these hidden signals beamed anything from elevator music and stock tickers to specialized content for medical professionals. Tuning into your favorite FM stations, you’d never notice them—unless you had the right hardware and a bit of know-how.

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