Hackaday Prize 2023: Hearing Sirens When Drivers Can’t

May 25, 2023 by Donald Papp 25 Comments

[Jan Říha]’s PionEar device is a wonderful entry to the Assistive Tech portion of the 2023 Hackaday Prize. It’s a small unit intended to perch within view of the driver in a vehicle, and it has one job: flash a light whenever a siren is detected. It is intended to provide drivers with a better awareness of emergency vehicles, because they are so often heard well before they are seen, and their presence disrupts the usual flow of the road. [Jan] learned that there was a positive response in the Deaf and hard of hearing communities to a device like this; roads get safer when one has early warning.

Deaf and hard of hearing folks are perfectly capable of driving. After all, not being able to hear is not a barrier to obeying the rules of the road. Even so, for some drivers it can improve awareness of their surroundings, which translates to greater safety. For the hearing impaired, higher frequencies tend to experience the most attenuation, and this can include high-pitched sirens.

The PionEar leverages embedded machine learning to identify sirens, which is a fantastic application of the technology. Machine learning, after all, is a way to solve the kinds of problems that humans are not good at figuring out how to write a program to solve. Singling out the presence of a siren in live environmental audio definitely qualifies.

We also like the clever way that [Jan] embedded an LED light guide into the 3D-printed enclosure: by making a channel and pouring in a small amount of white resin intended for 3D printers. Cure the resin with a UV light, and one is left with an awfully good light guide that doubles as a diffuser. You can see it all in action in a short video, just under the page break.

Continue reading “Hackaday Prize 2023: Hearing Sirens When Drivers Can’t” →

The Peak Of Vacuum Tube Radio Design

May 12, 2023 by Bryan Cockfield 19 Comments

One of the more popular trends in the ham radio community right now is operating away from the shack. Parks on the Air (POTA) is an excellent way to take a mobile radio off-grid and operate in the beauty of nature, but for those who want to take their rig to more extreme locations there’s another operating award program called Summits on the Air (SOTA) that requires the radio operator to set up a station on a mountaintop instead. This often requires lightweight, low-power radios to keep weight down for the hike, and [Dan] aka [AI6XG] has created a radio from scratch to do just that.

[Dan] is also a vacuum tube and CW (continuous wave/Morse code) operator on top of his interest in summiting various mountains, so this build incorporates all of his interests. Most vacuum tubes take a lot of energy to operate, but he dug up a circuit from 1967 that uses a single tube which can operate from a 12 volt battery instead of needing mains power, thanks to some help from a more modern switch-mode power supply (SMPS). The SMPS took a bit of research, though, in order to find one that wouldn’t interfere with the radio’s operation. That plus a few other modern tweaks like a QCX interface and a switch to toggle between receive to transmit easily allows this radio to be quite versatile when operating while maintaining its portability and durability when summiting.

For those looking to replicate a tube-based radio like this one, [Dan] has made all of the schematics available on his GitHub page. The only other limitation to keep in mind with a build like this is that it tends to only work on a very narrow range of frequencies without adding further complexity to the design, in this case within the CW portion of the 40-meter band. But that’s not really a bad thing as most radios with these design principles tend to work this way. For some other examples, take a look at these antique QRP radios for operating using an absolute minimum of power.

A 4-Player Arcade Hidden Inside A Coffee Table

May 11, 2023 by Dave Rowntree 3 Comments

[Ed] from 50% Awesome on YouTube wanted to build a retro gaming system with a decent screen size, but doesn’t have a great deal of space to site it in, so a good compromise was to make a piece of useful furniture and hide all the fun parts inside.

Building an arcade machine usually involves a lot of wiring

This video two-part build log shows a lot of woodwork, with a lot of mistakes (happy accidents, that are totally fine) made along the way, so you do need to repeat them. Essentially it’s a simple maple-veneered plywood box, with a thick lid section hosting the display and some repositioned speakers. This display is taken from a standard LG TV with the control PCB ripped out. The power button/IR PCB was prised out of the bezel, to be relocated, as were the two downwards-facing speakers. The whole collection of parts was attached to a front panel, with copious hot glue, we just hope the heavy TV panel was firmly held in there by other means!

Continue reading “A 4-Player Arcade Hidden Inside A Coffee Table” →

Laptop Motherboard? No, X86 Single-Board Computer!

February 27, 2023 by Arya Voronova 47 Comments

Sometimes a Raspberry Pi will not cut it – especially nowadays, when the prices are high and the in-stock amounts are low. But if you look in your closet, you might find a decently-specced laptop with a broken screen or faulty hinges. Or perhaps someone you know is looking to get rid of a decent laptop with a shattered case. Electronics recycling or eBay, chances are you can score a laptop with at least some life left in it.

Let’s hack! I’d like to show you how a used laptop motherboard could be the heart of your project, and walk you through some specifics you will want to know.

And what a great deal it could be for your next project! Laptop motherboards can help bring a wide variety of your Linux- and Windows-powered projects to life, in a way that even NUCs and specialized SBCs often can’t do. They’re way cheaper, way more diverse, and basically omnipresent. The CPU can pack a punch, and as a rule PCIe, USB3, and SATA ports are easily accessible with no nonsense like USB-throttled Ethernet ports.

Continue reading “Laptop Motherboard? No, X86 Single-Board Computer!” →

DIY Mini Fridge Is Pure Brilliance In Foam

February 18, 2023 by Lewin Day 54 Comments

There’s nothing more pleasing on a hot day than an ice-cold beverage. While the vast majority of us have a fridge in the kitchen, sometimes it’s desirable to have a further fridge in the lab, games room, or workshop. To that end, you may find value in this ultra-cheap, low-cost DIY fridge build from [Handy_Bear].

Like many tiny fridge builds, this design eschews complex gas-cycle refrigeration techniques for simple Peltier modules. These are devices that have one cold side and one hot side, because they move heat when electricity is applied. This build uses a Peltier module fitted with a fan to better shift away heat from the hot side, improving the module’s cooling ability.

The “fridge” itself is assembled out of thick XPS insulation foam. A hot wire cutter was used to cut several slabs which were then assembled using hot glue. The Peltier module is installed on the back, at the top of the fridge. Thus, air which is cooled in this area will then travel down through the rest of the fridge’s cavity. [Handy_Bear] also goes over how to produce a working hinge and a gasket for the door, which helps with ease-of-use and efficiency. As a nice touch, a set of 12V LED lights are also installed inside, which light when the door is open. Just like the real thing!

The final build is noisy, slow to cool down, and it uses 60 watts of power to cool down just two regulation-sized sodas. Notably, you could fit two standard NATO smoke grenades in the same space, as they’re almost-identically sized (ask us how we know). However, smoke grenades don’t usually need to be refrigerated.

None of that means it isn’t fun though! Plus, [Handy_Bear] notes that adding a second Peltier would greatly aid the fridge’s ability to quickly chill your ~~grenades~~ sodas. You might even like to explore the use of special fan designs to make the fridge even quieter! Video after the break.

Continue reading “DIY Mini Fridge Is Pure Brilliance In Foam” →

Self-Watering Planters Reuse Household Jars

January 29, 2023 by Donald Papp 9 Comments

Self-watering planters are low-maintenance, and common DIY projects. What we like most about [Tommy]’s design is that it reuses empty jars to create self-watering planters. After all, jars are fantastic at reliably holding water, so why not put them to work? Incorporating jars as part of the design means fewer worries about leakage, but it also means less 3D printing is needed overall.

A wick (in this case, a piece of string) takes care of moving water from jar to the soil.

[Tommy]’s planter screws onto the threads of a jar’s neck. Getting water to the plant is helped by a small piece of string, which acts as a wick between the soil at the top and the water in the jar at the bottom. This design works best with small plants, but on the plus side there are no moving parts or other complexities. Got a 3D printer? Models for the planter are available here.

The biggest challenge for this design is that not all jar threads are alike, so planters made in this way are not completely interchangeable across all different types of jars. Fortunately, [Tommy] provides the OpenSCAD code he used to generate his design, which he created with the help of an industry guide on how to measure the finish (or threads) of jars and lids.

If you find yourself needing to further customize your own version to fit a particular container’s threads, there’s no need to start from scratch. Unsurprisingly, threads and lids are highly standardized so chances are there exists a calculator, tool, or existing model for exactly what you need.

Off-Grid Van Build Uses 3D Scanning For Smarter Planning

January 22, 2023 by Donald Papp 44 Comments

Folks who refurbish and rebuild vans into off-grid campers (especially with the ability to work in them remotely) put a fantastic amount of planning and work into their projects. [Rob] meticulously documented his finished van conversion and while he does a ton of clever work, we especially liked how he shows modern tools like photogrammetry can improve the process.

Photogrammetry helped turn a bunch of photos from different angles into a textured 3D model with accurate dimensions.

[Rob] used a camera and photogrammetry software to 3D scan the van inside and out. The resulting model means that CAD tools can better assist with the layout and design phase. This is an immense help, because as [Rob] points out, an empty van is anything but a hollow box on wheels. Every surface is curved, none of the sides are identical, and there frankly isn’t a right angle to be found anywhere. When every little scrap of space counts, it’s important to have an accurate reference.

Of course, mapping the work are was just the beginning. It took six months, but he turned a Volkswagen Crafter cargo van into a slick off-grid camper capable of remote work. The full series of videos is on his site, but you can also watch the video highlights, embedded below.

The photogrammetry was done with Meshroom, and if you’d like to know more, we’ve previously explained different 3D scanning methods and how they can help with design work like this.

Continue reading “Off-Grid Van Build Uses 3D Scanning For Smarter Planning” →