Retro Gadgets: I Swear Officer, I Was Listening To 45

May 9, 2023 by 15 Comments

Audio in cars has a long history. Car radios in the 1920s were bulky and expensive. In the 1930s, there was the Motorola radio. They were still expensive — a $540 car with a $130 radio — but much more compact and usable.  There were also 8-tracks, cassettes, CDs, and lately digital audio on storage media or streamed over the phone network. There were also record players. For a brief period between 1955 and 1961, you could get a car with a record player. As you might expect, though, they weren’t just any record players. After all, the first thing to break on a car from that era was the mechanical clock. Record players would need to be rugged to work and continue to work in a moving vehicle. As you might also expect, it didn’t work out very well.

It all started with Peter Goldmark, the head of CBS Laboratories. He knew a lot about record players and had been behind the LP — microgroove records that played for 22 minutes on a side at 33.3 RPM instead of 5 minutes on a side at 78 RPM. He knew that a car record player needed to be smaller and shock-resistant. Of course, in those days, it would have tubes, but that could hardly be helped.

The problem turned into one of size. A standard 10- or 12-inch disk is too big to easily fit in the car. A 45 RPM record would be more manageable, but who wants to change the record every three or four minutes while driving?

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Moisture Duck Gives You A Green Thumb

May 9, 2023 by 19 Comments

Around the Hackaday bunker, any plant other than a cactus has a real chance of expiring due to thirst. Perhaps we should build some of [MakersFunDuck]’s Moisture Duck boards. As you can see in the video below, the simple PCB with an ATtiny13A tells you when it is time to water the plants. The video also covers several exotic methods of determining the watering status, some of which are pretty complex.

The board is simple because the operation of the device is simple. A fixed resistor creates a voltage divider with the soil, and dry soil has higher resistance than moist soil. A pot sets a threshold, and the microcontroller measures the voltages.

Of course, if you can’t remember to water the plants, you probably can’t remember to change batteries either. So the device sleeps most of the time, and only wakes up every eight seconds to conserve battery. It would be nice to alarm on a low battery, and, honestly, we would probably have made the sleep time longer.

The video covers how he minimizes corrosion, but we aren’t sure how well the board will survive in damp soil, but with a little protection, it might last a while. Besides that, you could probably just consider them almost disposable.

If you are really lazy, you can also automate the actual watering. You can even build that into a smart flower pot.

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Share Your Projects: Making Helpful PCBs

May 9, 2023 by 38 Comments

When it comes to things that hackers build, PCBs are a sizeable portion of our creative output. It’s no wonder – PCB design is a powerful way to participate in the hardware world, making your ideas all that more tangible with help of a friendly PCB fab. It’s often even more lovely when the PCB has been designed for you, and all you have to do is press “send” – bonus points if you can make a few changes for your own liking!

A lot of the time, our projects are untrodden ground, however, and a new design needs to be born. We pick out connectors, work through mechanical dimensions, figure out a schematic and check it with others, get the layout done, and look at it a few more times before sending it out for production. For a basic PCB, that is enough – but of course, it’s no fun to stop at ‘basic’, when there’s so many things you can do at hardly any cost.

Let’s step back a bit – you’ve just designed a board, and it’s great! It has all the chips and the connectors you could need, and theoretically, it’s even supposed to work first try. Now, let’s be fair, there’s an undeniable tendency – the more PCBs you design, the better each next one turns out, and you learn to spend less time on each board too. As someone with over two hundred PCBs under her belt, I’d like to show you a bunch of shortcuts that make your PCB more helpful, to yourself and others.

There’s a few ways that you can share your PCB projects in a more powerful way – I’d like to point out a few low-hanging fruits, whether README.md files or markings on the PCB itself. I’ve been experimenting quite a bit with external and embedded documentation of PCBs, as well as PCB sharing methods, got some fun results, and I’d like to share my toolkit through a few punchy examples and simple tricks. I’d also like to hear about yours – let’s chat! Continue reading “Share Your Projects: Making Helpful PCBs” →

Minimal USB Device Connects With Just A Couple Of Resistors

May 9, 2023 by 10 Comments

If you’re like most of us, your basic approach to building something boils down to: “What’s the minimum amount I need to do to get this to work?” It’s not a bad strategy in general, but the minimal build is rarely enough to meet all the requirements, as this extremely minimal but functional USB device illustrates.

Functional, yes, but as [TM] explains, only if you define functional as being recognized by your operating system. The BOM for that job turns out to be really small — a 3.3-volt regulator, its capacitor, and a pair of resistors connected to a DIP switch. The resistors, 1.5k each, are connected to the D+ and D- lines of the USB connector and pull their respective lines up to 3V3 when their switch is closed. If the D- switch is thrown, it indicates a low-speed connection is requested, while D+ requests a speedier connection. Either way, its enough to get the familiar “USB connect” sound in Windows, and to see it listed in Device Manager or dmesg on Linux.

With no microcontroller to return a device descriptor, not much else happens, of course, but it’s still interesting that so little is needed to at least get the host machine to know that something was plugged in. And that alone has some diagnostic value; as [TM] points out, you could use this circuit to test that the physical port on the host at least minimally works.

He runs through a few other potentially useful scenarios, but really, the best use of something like this is to educate yourself on the lowest levels of USB connection negotiation. If you want to dive deeper into USB-C specifically, we suggest you check out [Arya Voronova]’s “All About USB-C” series.

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Giving A Tinge Of Color To The Mars Map Courtesy Of The UAE’s Hope Orbiter

May 9, 2023 by No comments

Since the United Arab Emirates’ Hope (“Al-Amal”) orbiter made it safely into orbit around Mars on February 9, 2021, it’s been busy using its onboard instruments to measure everything it could about not only the planet’s atmosphere but also its surface and how both change seasonally. The first months of results of these detailed captures of Mars have now been released in the form of the full-color Mars Atlas website, and a pretty well made PDF version of the Atlas that can be downloaded from the website.

Although the Emirates Mars Mission is not the first to capture the surface or seasons of Mars — with the Mars Reconnaissance Orbiter (MRO)’s Context Camera  (CTX) having gifted us the result of many thousands of captures in a massive monochrome mosaic of Mars’ surface — it’s good to remember that Hope is only just getting started. The current atlas is the result of about 3,000 captures from the Emirates eXploration Imager (EXI) multi-band camera (with better than 8 km spatial resolution), with new images in the pipeline.

Hope has transitioned from a low 1,072 km orbit to a higher, science orbit on March 29, which gives the orbiter a good view of the seasonal transitions on the Red Planet. Along with data from other current Mars orbiters, we should be able to piece together the most detailed atlas yet, even before more helicopters will zip along Mars’ surface.

Arctos Robotics: Build A Robot Arm Out Of 3D Printer Spares?

May 8, 2023 by 11 Comments

ARCTOS is a 6-DOF robot arm based upon 3D printed mechanics running a modified version of GRBL firmware. Let’s get this straight now, the firmware is open source, but the hardware plans are a paid download, but for less than forty euros, we reckon the investment would be well worth it, judging from the quality of the build instructions and the software support already in place. Continue reading “Arctos Robotics: Build A Robot Arm Out Of 3D Printer Spares?” →

A 3D printed copper aerospike engine cutaway showing the intricate, organic-looking channels inside. It is vaguely reminiscent of a human torso and lungs.

3D Printed Aerospike Was Designed By AI

May 8, 2023 by 36 Comments

We’re still in the early days of generatively-designed objects, but when combined with the capabilities of 3D printing, we’re already seeing some interesting results. One example is this new copper aerospike engine. [via Fabbaloo]

A collaboration between startups Hyperganic (generative AI CAD) and AMCM (additive manufacturing), this 800 mm long aerospike engine may be the most complicated 3D print yet. It continues the exciting work being done with 3D printing for aerospace applications. The complicated geometries of rocket nozzles of any type let additive manufacturing really shine, so the combination of generative algorithms and 3D printed nozzles could result in some big leaps in coming years.

Aerospikes are interesting as their geometry isn’t pressure dependent like more typical bell-shaped rocket nozzles meaning you only need one engine for your entire flight profile instead of the traditional switching mid-flight. A linear aerospike engine was one of the main selling points for the cancelled VentureStar Space Shuttle replacement.

This isn’t the only generative design headed to space, and we’ve covered a few projects if you’re interested in building your own 3D printed rocket nozzles or aerospike engines. Just make sure you get clearance from your local aviation regulator before your project goes to space!