MUDLink Is Making UART Data Links More Reliable

Many of us have used UARTs to spit data from one system or chip to another. Normally, for quick and dirty maker projects, this is good enough. However, you’ll always get the odd dropped transmission or glitch that can throw a spanner in the works if you’re not careful. [Jake Read] decided to work on a system that could use UARTs while being far more reliable. Enter MUDLink.

MUDLink is a library that works with an Arduino’s UART port and stacks on a bit of protocol to clean things up. It uses a packetized method of sending data to ensure that transmissions are received reliably as intended by the sender. Packets are framed using a method called Consistent Overhead Byte Stuffing, which is a nice lightweight way of doing so. The system also uses CRC16-CCITT as an error checking mechanism. There’s also an ack-and-retransmit system for ensuring any dropped transmissions are repeated and received successfully.

If you need reliable UART transmissions without too much overhead, you might want to look at what Jake is doing. It’s a topic we’ve looked at before, too.

Start Your Creepy Jack-O-Lantern Project Early This Year With Gourdan

For a lot of us, projects take time, and they have to be squeezed in around the regular chores of real life. Thus, if you’re starting your Halloween builds after the holiday displays have already hit the stores, you’re probably too late. We’re here to implore you to start building early this year—and you can take inspiration from a great pumpkin called Gourdan.

Gourdan is the work of [Braden Sunwold]. It’s a pumpkin with a fearsome visage and creepy eyes that follow you around the room. This is achieved thanks to a Raspberry Pi 3 nestled within Gourdan’s gourdy body. Gourdan’s eyes are a pair of 1.54-inch LCDs which display animated eyes. Thus, no mechanical wizardry is required here—it’s all done digitally. A camera attached to the Raspberry Pi tracks people with the aid of OpenCV, and the eyes are created and animated with the help of Adafruit example code.

There’s never a better time to start hacking for Halloween than right now. And hey, who knows—your neighbour might have kicked off in January, so they’ll have an almighty head start. They could have something really impressive in the works!

And don’t forget—you can always send us your holiday hacks, whatever the time of year! Just hit up the tipsline. Happy making!

3D Printed Wheels Passively Transform To Climb Obstacles

Wheels do a great job at rolling over all kinds of terrain, particularly if you pair them with compliant tires. However, they’re not perfect, and can get stumbled by things like large vertical steps. Enter the PaTS-Wheel — a compliant mechanism that can tackle such obstacles with ease.

The PaTS-Wheel takes advantage of printable flexural hinges. Under regular conditions, it exists as a simple round wheel. However, when presented with a step obstacle, its individual segments can bend and flex to grab on to the step and hoist the vehicle up. It all happens passively as a result of the wheel’s structure, no actuators or control system are needed to achieve this action.

The video below does a great job of explaining the concept in raw engineering terms, as well as showing it in action. If you really want to drill down though, dive into the research paper. The design outperformed smooth wheels and whegs in climbing ability, and was able to match smooth wheels in simple tests of flat ground power consumption. The results are very impressive.

We’ve seen other transforming wheels before, like these wheg-like constructions, but nothing so passive and elegant as these. Video after the break.

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NASA Is Now Tasked With Developing A Lunar Time Standard, Relativity Or Not

A little while ago, we talked about the concept of timezones and the Moon. It’s a complicated issue, because on Earth, time is all about the Sun and our local relationship with it. The Moon and the Sun have their own weird thing going on, so time there doesn’t really line up well with our terrestrial conception of it.

Nevertheless, as humanity gets serious about doing Moon things again, the issue needs to be solved. To that end, NASA has now officially been tasked with setting up Moon time – just a few short weeks after we last talked about it! (Does the President read Hackaday?) Only problem is, physics is going to make it a damn sight more complicated!

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Building A Mechanical Keyboard As A Learning Project

[Thomas Rinsma] wanted to learn about designing PCBs. Thus, he set about a nifty project that would both teach him those lessons and net him something useful in the process. The result was kb1, a mechanical keyboard of his own design!

You might think [Thomas] would have started with a basic, barebones design, but he didn’t shy away from including some neat features. His keyboard has a “tenkeyless” layout, and uses Cherry MX-style switches, as has become the norm in the mechanical keyboard world. It has a 16×2 LCD display for user feedback, a rotary encoder, and it even has an RGB backlight for every key thanks to SK6812 addressable LEDs. Running the show is a Raspberry Pi Pico, equipped with the KMK firmware. The board actually uses twin PCBs as the enclosure, which is a nifty trick.

It’s remarkably fully featured for a first time build.

This Arduino Is Feeding The Fishes

Depending on the species, a fish can be a fairly low-maintenance pet. But of course even the most laid back of creatures needs to eat, so you’ll have to make sure to feed them regularly. If you’re a fish owner who would like to simplify tending to your creatures, you might find value in this project from [CrazyScience].

This fish feeder is based on an Arduino Uno, the 8-bit microcontroller development board which has done so much for so many. The Arduino drives a stepper motor, which rotates a 3D printed disc mechanism for dispensing food. Each slot of the disc is loaded with a small amount of fish food, so that when it rotates, a slot dumps its contents through a slot into the water.

Activating the system is as easy as a wave of the hand. That’s thanks to an ultrasonic sensor, which detects movement close by, and triggers the food delivery mechanism in turn. We’d love to see this upgraded with a timer mode too, though it would require the addition of a real-time clock module to the humble Arduino Uno.

It’s a simple project, but one that teaches all kinds of useful skills, from programming to design and 3D printing. We just worry that the fish bowl in the demo is a far too small for fish to remain healthy. We’ve seen some other similar projects before, too.

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Cheap Musical Tesla Coil Put Through Its Paces

Once upon a time, musical Tesla coils were something you primarily saw at high-voltage hobby meets. They’ve become more popular in recent years, and now you can even buy cheap examples online. [mircemk] decided to buy one and gave it a whirl.

The device comes with a power supply capable of delivering 2 amps at 48 V.  It’s a solid-state design, relying on SMD MOSFETs to generate high-voltage, high-frequency output that makes the sparks we all know and love. The pancake coil is key to the design, and is made using a trace on the PCB — a neat technique compared to making one with a laborious winding operation.

The coil can be used to simply generate sparks, or it can be modulated musically. In this mode of operation, it’s intended to be driven by square wave audio for simplicity’s sake. As seen in [mircemk]’s video, the sound quality is pretty decent for a cheap device, and the Super Mario theme is readily recognizable. As a guide, he also demonstrates how to drive the device using an Arduino set up for square wave audio output.

If you prefer to build your own singing Tesla coil, you can go that route instead. Or, you could buy one of these and hack it, and drop us a line with what you come up with! Similar devices are all over the ‘net. Continue reading “Cheap Musical Tesla Coil Put Through Its Paces”