All of the technological improvements to vehicles over the past few decades have led to cars and trucks that would seem borderline magical to anyone driving something like a Ford Pinto in the 1970s. Not only are cars much safer due to things like crumple zones, anti-lock brakes, air bags, and compulsory seat belt use, but there’s a wide array of sensors, user interfaces, and computers that also improve the driving experience. At least, until it starts wearing out. The electronic technology in our modern cars can be tricky to replace, but [Aravind] at least was able to replace part of the instrument cluster on his aging (yet still modern) Skoda and improve upon it in the process.

These cars have a recurring problem with the central part of the cluster that includes an LCD display. If replacement parts can even be found, they tend to cost a significant fraction of the value of the car, making them uneconomical for most. [Aravind] found that a 3.5″ color LCD that was already available fit perfectly in the space once the old screen was removed, so from there the next steps were to interface it to the car. These have a CAN bus separated from the main control CAN bus, and the port was easily accessible, so an Arduino with a RTC was obtained to handle the heavy lifting of interfacing with it.

Now, [Aravind] has a new LCD screen in the console that’s fully programmable and potentially longer-lasting than the factory LCD was. There’s also full documentation of the process on the project page as well, for anyone else with a Volkswagen-adjacent car from this era. Either way, it’s a much more economical approach to replacing the module than shelling out the enormous cost of OEM replacement parts. Of course, CAN bus hacks like these are often gateway projects to doing more involved CAN bus projects like turning an entire vehicle into a video game controller.

If you suffer from nostalgia, you might remember carving a block of wood into a car, adding some wheels, and racing it against other contestants in a pinewood derby. Today’s derby is decidedly high tech though, and we were impressed with this car scale that also figures out the car’s center of gravity.

Based on an Arduino, of course, along with a pair of HX711 load cells. Why a pair? That’s how the device measures the center of gravity is by weighing the front and rear of the car separately.

We really liked the wooden case and found the use of wood satisfying if not ironic. Our only input is that since you need the wheelbase of the car to do the CG calculations, we’d have glued a ruler down. On the other hand, probably any self-respecting pinewood derby creator knows their wheelbase by heart.

Why does CG matter? If you are too far forward, you lose some acceleration. If you are too far back, the front wheels might pop up. With this device, you can know exactly where your center is and make adjustments accordingly.

If you’d rather build something for the actual race, why not a photo finish system? Or, perhaps you need a jet-powered (illegal) entry.

Walking robots were once the purview of major corporations spending huge dollars on research programs. Now, they’re something you can experiment with at home. [Technovation] has been doing just that with his micro quadruped build.

The build runs twelve servos – three per leg – to enable for a great range of movement for each limb. The servos are all controlled by an Arduino Uno fitted with an Arduino Sensor Shield. Everything is fitted together with a 3D printed chassis and limb segments that bolt directly on to the servo output shafts. This is a common way of building quick, easy, lightweight assemblies with servos, and it works great here. Inverse kinematics is used to calculate the required motions of each joint, and the robot can take steps from 1 to 4cm long in a variety of gaits.

We’d love to see a few sensors and a battery pack added on to allow the ‘bot to explore further in an untethered fashion. [Technovation] has left some provision to mount extra hardware, so we look forward to seeing what comes next.

We’ve seen bigger quadrupeds do great things, too. Video after the break.

Like us, [Alberto] doesn’t compromise when it comes to a good cup of coffee. We figure that if he went to an office in the Before Times, he was the type of coworker to bring in their own coffee equipment so as not to suffer the office brew. Or perhaps he volunteered to order the office supplies and therefore got to decide for everyone else. Yep, that’s definitely one way to do it.

But like many of us, he is now operating out of a home office. Even so, he’s got better things to do than stand around pouring the perfect cup of coffee every morning. See, that’s where we differ, [Alberto]. But we do love Cafeino, your automated pour-over machine. It’s so sleek and lovely, and we’re sure it does a much better job than we do by hand — although we enjoy doing the pouring ourselves.

Cafeino is designed to mimic the movements of a trained barista’s hand, because evidently you’re supposed to pour the water in slow, deliberate swirls to evenly cover the grounds. (Our kettle has a chunky spout, so we just sort of wing it.) Cafeino does this by pumping water from an electric kettle and pouring a thin stream of it in circles with the help of two servos.

The three buttons each represent a different recipe setting, which specifies the amount of water, the hand pouring pattern, and the resting times between blooming the grounds and actually pouring the bulk of the water. These recipes are set using the accompanying web app via an ESP32, although the main brain barista is an Arduino Nano. Grab a cup and check out the demo after the break.

Got an old but modern coffee robot lying around? You could turn it into a planter with automated watering.

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It’s an old misconception that digital musicians just use a mouse and keyboard for their art. This is often far from the truth, as many computer music artists have a wide variety of keyboards/synths, MIDI controllers, and “analog” instruments that all get used in their creative process. But what if one of those instruments was just a mouse?

Well, that must have been what was going through [kzra]’s mind when he turned an old ps/2 roller ball mouse into an electronic instrument. Born out of a love for music and a hate for waste, the mouse is a fully functional MIDI controller. Note pitch is mapped to the x-coordinate of the pointer, and volume (known as velocity, in MIDI-speak) is mapped to the y-coordinate. The scroll wheel can be used as a mod wheel, user-configurable but most often used to vary the note’s pitch. The mouse buttons are used to play notes, and can behave slightly differently depending on the mode the instrument is set to.

Not satisfied with simply outputting MIDI notes, [kzra] also designed an intuitive user interface to go along with the mouse. A nice little OLED displays the mode, volume, note, and mouse coordinates, and an 8×8 LED matrix also indicates the note and volume. It’s a fantastic and versatile little instrument, and you’ve gotta check out the video after the break to see it for yourself. We’ve seen some awesome retro-tech MIDI controllers before, and this fits right in.

Thanks to [midierror] for the tip!

We’ve all found ourselves swimming amongst too many similar-looking USB cables over the years. Some have all the conductors and functionality, some are weird power-only oddballs, and some charge our phones quickly while others don’t. It’s a huge headache and one that [TechKiwiGadgets] hopes to solve with the Arduino Cable Tracer.

The tracer works with USB-A, Mini-USB, Micro-USB, and USB-C cables to determine whether connections are broken or not and also to identify wiring configurations. It’s built around the Arduino Mega 2560, which is ideal for providing a huge amount of GPIO pins that are perfect for such a purpose. Probing results are displayed upon the 2.8″ TFT LCD display that makes it easy to figure out which cables do what.

It’s a tidy build, and one that we could imagine would be very useful for getting a quick go/no-go status on any cables dug out of a junk box somewhere. Just remember to WIDLARIZE any bad cables you find so they never trouble you again. Video after the break.

Want to display a PNG file on a display attached to an Arduino or other microcontroller board? You’ll want to look at [Larry Bank]’s PNGdec, the Arduino-friendly PNG decoder library which makes it much easier to work with PNG files on your chosen microcontroller.

The PNG image format supports useful features like lossless compression, and was generally developed as an improved (and non-patented) alternative to GIF files. So far so great, but it turns out that decoding PNG files on a microcontroller is a challenge due to the limited amount of memory compared to desktop machines. When the PNG specification was developed in the 90s, computers easily had megabytes of memory to work with, but microcontrollers tend to have memory measured in kilobytes, and lack high-level memory management. [Larry]’s library addresses these issues.

PNGdec is self-contained and free from external dependencies, and also has some features to make converting pixel formats for different display types easy. It will run on any microcontroller that can spare at least 48 K of RAM, so if that sounds useful then check out the GitHub repository for code and examples.

We’ve seen [Larry]’s wonderful work before on optimizing GIF playback as well as rapid JPEG decoding, and these libraries have increasing relevance as hobbyists continue to see small LCD and OLED-based displays become ever more accessible and affordable.

[PNG logo: PNG Home Site]

One way of communicating with autistic and non-verbal people is through the use of a Picture Exchange Communication System or PECS board, which they can use to point out what they need or want throughout the day. However, the commercial versions of these boards have their share of problems — they’re expensive, and they’re fairly rigid as far as the pictures go. [Alain Mauer] has created an open-source PECS board that is far more personalized, and has audio to boot.

The number one requisite here is sturdiness, as [Alain]’s son [Scott] has already smashed two smartphones and a tablet. [Alain] went with a laser-cut MDF enclosure that should last quite a while. Inside is an Arduino Pro Mini and a DF Player Mini that plays corresponding clips from a micro SD card whenever [Scott] presses a button on the 16-key copper foil capacitive keypad. This PECS board is smart, too — it will sound a turn-me-off reminder after a few minutes of inactivity, and issue audible low battery warnings.

So far, [Scott] is responding better to photographs of objects than to drawings. Watch him interact with the board after the break.

This is far from the first thing [Alain] has built to help [Scott]. Be sure to check out this Pi-based media player built to engage and not enrage.

At Hackaday, we celebrate all kinds of projects, but we’ll have to admit that the polished and professional-looking builds tend to catch our eye a lot more than perhaps they should. There’s plenty of love to be had for the rougher builds, though, of which this quick-and-dirty home automation system is a perfect example.

Before anyone rushes to state the obvious with, “Should have used some relays,” consider that [MAKE_IT_WITH_ME]’s stated goal was to get the basics of a home automation system built with pretty much nothing but what can be found in one of those Arduino starter kits. And further, consider that landlords might not look kindly on tenants who wire a bunch of SSRs or Sonoff switches into the walls of their building. So this minimalist build is perfect for certain use cases. Its interface to the building’s electrical system is 100% mechanical, via a servo that travels along the bank of switches on a stepper-driven leadscrew. The servo has a modified horn to properly flick the rocker-style switches, and although changing from switch to switch is a bit slow, it works surprisingly well. The video below shows it in action.

While we can see it possibly working as-is for Decora-style switches that are seen in some markets, we’d think some mods would be in order for the more standard toggle-style switch — perhaps a finger extending out from the horn, along with a second servo to tilt the whole assembly away from the wall to allow it to clear the switch bats.

The inner machinations of the mind of cryptocurrency markets are an enigma. Even traditional stock markets often seem to behave at random, to the point that several economists seriously suggest that various non-human animals might outperform one market or another just by random chance alone. The classic example is a monkey picking stocks at random, but in the modern world the hamster [Mr Goxx] actively trades crypto from inside his hamster cage.

[Mr Goxx]’s home comprises a normal apartment and a separate office where he can make his trades. The office contains an “intention wheel” where he can run in order to select a currency to trade, and two tunnels that [Mr Goxx] can use to declare his intention to buy or sell the currency he selected with the wheel. The wheel is connected to an Arduino Nano with an optical encoder, and the Nano also detects the hamster’s presence in the “buy” or “sell” tunnel and lights up status LEDs when he wants to execute a trade. The Nano also communicates with an intricate Java program which overlays information on the live video feed and also executes the trades in real life with real money.

Live updates are sent directly both on Twitter and Reddit, besides the live Twitch stream of [Mr Goxx] we linked above. The stream only shows his office and not his apartment, and he’s mostly active at night (Berlin time). But we can’t wait for his random walks to yield long-term results which can be analyzed for years to come. In the meantime we’ll see if others have been able to make any profits in crypto with any less-random methods.