Laser Cut Clips Save A Lamp From The Trash

December 25, 2022 by Jenny List 6 Comments

Ikea have been known for years as a purveyor of inexpensive yet stylish homewares, but it’s fair to say that sometimes their affordability is reflected in their insubstantial construction. Such is the case with the Sjöpenna lamp, whose construction relies on rubber bands. On [Tony]’s lamp these bands degraded with age, causing it to fall apart. The solution? A set of cleverly-designed laser-cut clips to replace them.

The challenge to replacing a stretchy material with a rigid one is that it must have enough ability to bend without snapping as it is put in place. For this he selected PETG, with 0.04″ (about 1 mm thick) hitting the sweet spot. His photos demonstrate with some green tape added for visibility, how the clip bends backwards just far enough to fit over where the rubber band once located, and then flips back neatly to hold it all in place.

If you have a collapsing Ikea lamp then this will be just what you need, but this hack goes further than that. A frequent requirement for repairs is some kind of clip, because clips are always the first to break, This technique for laser cutting them is a handy one to remember, next time your design needs a springy bit of plastic.

GitHub ESP32 OTA Updates, Now In MicroPython Flavor

December 23, 2022 by Elliot Williams 5 Comments

Wouldn’t it be great if you could keep all of your small Internet-connected hacks up to date with a single codebase? A couple of weeks ago, we wrote up a project that automagically pulls down OTA updates to an ESP32 from GitHub, using the ESP32 C SDK. [Pascal] asked in the comments, “but what about MicroPython?” Gauntlet thrown, [TURFPTAx] wrote ugit.py – a simple library that mirrors all of the code from a public GitHub Python repo straight to your gizmo running Micropython.

[Damped] wrote in about Senko, another library that does something very similar, but by then [TURFPTAx] was already done. Bam! Part of the speed is that MicroPython includes everything you need to get the job done – parsing streamed JSON was the hard part with the original hack. MicroPython makes those sorts of things easy.

This is one of those ideas that’s just brilliant for a hacker with a small flock of independent devices to herd. And because ugit.py itself is fairly simple and readable, if you need to customize it to do your own bidding, that’s no problem either. Just be sure that when you’re storing your WiFi authentication info, it’s not publicly displayed. ([TURFPTAx], could I log into your home WiFi?)

What’s [TURFPTAx] going to be using this for? We’re guessing it’s going to be deploying code to his awesome Open Muscle sensing rigs. What will we be using it for? Blinky Christmas decorations for the in-laws, now remotely updatable without them having to even learn what a “repo” is.

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Snail Mail Notifier’s Simple Power Management To Maximize Battery Life

December 19, 2022 by Donald Papp 33 Comments

There are no weird, specialized components nor esoteric sleep mode tricks behind the long battery life of [Zak]’s WiFi mail slot watcher. Just some sensible design and clever focus on the device’s purpose: to send an HTTP request whenever it detects that the front door’s mail slot has been opened. The HTTP request is what kicks off useful notifications, but it’s the hardware design that’s really worth a peek.

The watcher’s main components are a ESP-M2 WiFi module, a reed switch, and a single lithium cell. Here’s how it works at a high level: when the mail slot is opened (detected by the reed switch), the ESP module is powered up just long enough to connect to the local WiFi network and send a single HTTP request, after which it shuts back down. The whole process takes between four and ten seconds.

As mentioned, the power control isn’t managed by any unusual components; it comes down to a NAND gate with a single inverted input, and a MIC5504 3.3 V regulator responsible for feeding the ESP board. The logic gate controls whether the voltage regulator is enabled or disabled, and therefore whether the microcontroller receives any power at all. Most of the time the regulator is disabled, but when the reed switch triggers, its input to the NAND gate is pulled low and the regulator is turned on, booting up the ESP board.

In order to stay on, the first thing the ESP board does is use a GPIO pin to drive the inverted input of the NAND gate high in order to keep the regulator enabled, and it has a window of about half a second to do this. Once the HTTP request is sent (and the battery voltage sensed), the ESP board pulls that pin low, disabling the regulator and turning itself off until the reed switch once again begins the process.

After seven months of use, the battery has dropped from 4.2 V to 3.9 V, so there’s plenty of life left. The project’s GitHub repository has the necessary code if you’d like to apply some of its ideas to your own projects. Alternately, you may wish to consider supercapacitors and solar in lieu of batteries. Even if ultra-level power savings isn’t your bag, when WiFi and networking is involved, there are software-level opportunities to be more efficient. Even a judicious 1 ms delay can save a surprising amount of power in the right circumstances.

Fixing (And Improving!) An Annoying Apartment Entry System

December 11, 2022 by Donald Papp 7 Comments

[Zak]’s two-floor apartment has a typical door entry control system, but the setup is less than ideally convenient. The wall-mounted telephone-like intercom is downstairs, but [Zak] is usually upstairs. What’s an enterprising hacker to do? Obviously the most elegant solution is to simply do without visitors in the first place, but [Zak] opted for a more full-featured solution to the problem.

The layout of the typical wall-mounted door intercom is less than ideal.

He fixed things with a custom ESP8285-based board that, with the help of opto-isolation, allows him to detect visitors and grant entry without having to be physically present at the wall-mounted intercom. It’s even integrated into Telegram, and has a few neat new features. Let’s take a look.

The first interesting bit is how [Zak] rolled his own opto-isolation. The door entry system uses 14 VAC and is frankly — electromagnetically-speaking — a very noisy device. Attaching GPIO pins directly to this system from the ESP board for interfacing is not an option. The solution in situations like this is to use opto-isolation, so that interfaced devices can be electrically isolated from one another.

Rather than use off-the-shelf options, [Zak] opted to keep things small and economical by rolling his own solution using side-mounted IR LEDs on the small interface PCB. LEDs can also act as photodiodes, so by pointing two LEDs directly at one another and driving one LED from the door control system and measuring the small amount of resulting current on the other LED, [Zak] can detect states without having to directly connect a GPIO pin.

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Using GitHub Actions To Brew Coffee

December 10, 2022 by Bryan Cockfield 27 Comments

It’s getting harder and harder to think of a modern premium-level appliance that doesn’t come with some level of Internet connectivity. These days it seems all but the cheapest refrigerators, air purifiers, and microwaves include wireless capabilities — unfortunately they’re often poorly implemented or behind a proprietary system. [Matt] recently purchased a high-end coffee maker with Bluetooth functionality which turned out to be nearly useless, and set to work reverse-engineering his coffee maker and adapting it to work by sending commands from GitHub.

Since the wireless connectivity and app for this coffee maker was so buggy and unreliable, [Matt] first needed to get deep into the weeds on Bluetooth Low Energy (BTLE). After sniffing traffic and identifying the coffee maker, he set about building an interface for it in Rust. Once he is able to send commands to it, the next step was to integrate it with GitHub, so that filing issues on the GitHub interface sends the commands from a nearby computer over Bluetooth to the coffee maker, with much more reliability than the coffee maker came with originally.

Using [Matt]’s methods, anyone stuck with one of these coffee makers, a Delonghi Dinamica Plus, should be able to reactivate the use of its wireless functionality. While we’d hope that anyone selling a premium product like this would take a tiny amount of time and make sure that the extra features actually work, this low bar seems to be oddly common for companies to surmount. But it’s not required to pick up an expensive machine like this just to remotely brew a cup of coffee. You can do that pretty easily with a non-luxury coffee maker and some basic wireless hardware.

Standing Desk With A Clever Flair

November 29, 2022 by Matthew Carlson 27 Comments

Standing desks (also known as sit-stand desks) are somewhat polarizing. The height is adjustable, but the idea is that you move between sitting and standing while you work. Hundreds of manufacturers are out there, but they’re all the same. Two metal legs that extend and one or more motors to move the legs up and down. [JAR Made] tried to make something slightly different for their standing desk with an extending curved surface.

The build started with some gorgeous alder that was milled into square with a track saw and a planer — no jointer was required. However, he wanted long boards and was debating how to butt join the pieces together and decided on pocket holes with dowels to try and clamp the boards together while the glue dried. The resulting product was one that [JAR Made] was unhappy with. He pivoted on his feet by switching Baltic birch plywood for the main desk surface. Which was bent using a kerf-cutting technique (though just using a track saw rather than a CNC bit).

Here is where you can see him learn from his earlier mistakes. He routed a half lap in the plywood for the butt joint to give it more strength and devised a clever clamping mechanism using CA glue and painter’s tape to get good clamping pressure. The alder from earlier came in use to serve as a front edge for the plywood and a groove to hold the sliding piece of plywood that extends and retracts as the desk goes up and down.

Regular old standing desk legs screw into the underside of the desk and allow it to move up and down. Overall, it’s a wonderful build of a gorgeous desk. We love seeing people make mistakes and then pivot and learn from them. Perhaps the next step is to automate the desk to move on its own.

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Turn Your Furniture Into A Light Show With Hyelicht

November 26, 2022 by Tom Nardi 18 Comments

There’s something about the regimented square shapes of the IKEA Kallax shelf that convinced [Eike Hein] it could benefit from some RGB LED lighting, and while he could have simply used a commercial solution, he decided instead to develop Hyelicht: an incredibly well documented open source lighting system featuring multiple control interfaces and APIs. We’d say it was overkill, but truth be told, we dream of a world where everyone takes their personal projects to this level.

In the boilerplate configuration, [Eike] shows off controlling the LEDs using a graphical user interface running on a Waveshare 7″ touch screen mounted to the side of the shelf. That’s the most direct way of controlling the LEDs, as the touch screen is plugged into the Raspberry Pi 4B that’s actually running the software. But the same interface can also be remotely accessed by your smartphone or desktop.

You can also skip the GUI entirely and control the LEDs with a command line interface, or maybe poke Hyelicht’s HTTP REST interface instead. The system can even integrate with the Philips Hue ecosystem, if you prefer going that route.

The 5×5 Kallax shelf is the project’s official reference hardware, but of course it will work with anything else you might wish to cover with controllable LEDs. We’ve seen similar setups used to light storage bins in the past, but nothing that can even come close to the documentation and customization possibilities offered by Hyelicht. This is definitely a project to keep a close eye on if you’ve got the urge to add a little color to your world.