Author: Bryan Cockfield

1513 Articles

The Design Process For A Tiny Robot Brain

October 20, 2024 by 13 Comments

As things get smaller, we can fit more processing power into devices like robots to allow them to do more things or interact with their environment in new ways. If not, we can at least build them for less cost. But the design process can get exponentially more complicated when miniaturizing things. [Carl] wanted to build the smallest 9-axis robotic microcontroller with as many features as possible, and went through a number of design iterations to finally get to this extremely small robotics platform.

Although there are smaller wireless-enabled microcontrollers, [Carl] based this project around the popular ESP32 platform to allow it to be usable by a wider range of people. With that module taking up most of the top side of the PCB, he turned to the bottom to add the rest of the components for the platform. The first thing to add was a power management circuit, and after one iteration he settled on a circuit which can provide the board power from a battery or a USB cable, while also managing the battery’s charge. As for sensors, it has a light sensor and an optional 9-axis motion sensor, allowing for gesture sensing, proximity detection, and motion tracking.

Of course there were some compromises in this design to minimize the footprint, like placing the antenna near the USB-C charger and sacrificing some processing power compared to other development boards like the STM-32. But for the size and cost of components it’s hard to get so many features in such a small package. [Carl] is using it to build some pretty tiny robots so it suits his needs perfectly. In fact, it’s hard to find anything smaller that isn’t a bristlebot.

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A Parts Bin MIDI Controller In 24 Hours

October 20, 2024 by 9 Comments

Part of the reason MIDI has hung on as a standard in the musical world for so long is that it is incredibly versatile. Sure, standard instruments like pianos and drums can be interfaced with a computer fairly easily using this standard, but essentially anything can be converted to a MIDI instrument with the right wiring and a little bit of coding. [Jeremy] needed to build a MIDI controller in a single day, and with just a few off-the-shelf parts he was able to piece together a musical instrument from his parts bin.

The build is housed in an off-brand protective case from a favorite American discount tool store, but the more unique part of the project is the choice to use arcade buttons as the instrument’s inputs. [Jeremy] tied eight of these buttons to an Arduino Uno to provide a full octave’s worth of notes, and before you jump to the comments to explain that there are 12 notes in an octave, he also added a button to the side of the case to bend any note when pressed simultaneously. An emergency stop button serves as a master on/off switch and a MIDI dongle on the other side serves as the interface point to a computer.

After a slight bit of debugging, the interface is up and running within [Jeremy]’s required 24-hour window. He’s eventually planning to use it to control a custom MIDI-enabled drum kit, but for now it was fun to play around with it in some other ways. He’s also posted the project code on a GitHub page. And, if this looks a bit familiar, this was not [Jeremy]’s first MIDI project. He was also the creator of one of the smallest MIDI interfaces we’ve ever seen.

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Self-Portaging Canoe Is Part Bicycle

October 19, 2024 by 10 Comments

Normally when making a long voyage in a canoe, an adventurer would paddle the vessel as far as possible and then “portage”, or carry, the canoe over the short sections of land separating the bodies of water. Portaging is a lot of work, though, since canoes generally aren’t particularly light or designed for traveling over land. To solve this problem, [Ben] is modifying his home-built canoe with some interesting parts to make it into an amphibious vehicle which can much more easily traverse land.

The wheels for the amphibious craft come from BMX bicycles, which have much smaller wheels as well as more robust frames when compared to more traditional bicycles. The rear of the canoe was modified to use a go-kart axle with two driven wheels. An additional set of cranks mounted outboard drive a custom-built paddle to propel the boat when traveling on water. The frame borrows heavily from recumbent bicycle design and includes a similarly comfortable seat, with steering handled by a wheel at the front when traveling on land and a rudder at the rear when traveling over water.

[Ben] intends to take this unique vehicle on a cross-country trip across Scotland, with the first part of the adventure on water via the Caledonian Canal and the return trip on land via the Great Glen Way. Hopefully, there’s no actual portaging required for his trip as the bike components add a tremendous amount of weight to the boat. [Ben] he even added a sail that could theoretically be used in either mode. We’ll be keeping watch for his next videos showing his adventure, and in the meantime daydreaming about other unique bikes that let you travel where bikes normally can’t.

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Access The Information Superhighway With A Mac Plus

October 17, 2024 by 5 Comments

For some time now, Apple has developed a reputation for manufacturing computers and phones that are not particularly repairable or upgradable. While this reputation is somewhat deserved, especially in recent years, it seems less true for their older machines. With the second and perhaps most influential computer, the Apple II, being so upgradable that the machine had a production run of nearly two decades. Similarly, the Macintosh Plus of 1986 was surprisingly upgradable and repairable and [Hunter] demonstrates its capabilities by bringing one onto the modern Internet, albeit with a few tricks to adapt the old hardware and software to the modern era.

The Mac Plus was salvaged from a thrift store, and the first issue to solve was that it had some rotten capacitors that had to be replaced before the computer could be reliably powered on at all. [Hunter] then got to work bringing this computer online, with the only major hardware modification being a BlueSCSI hard drive emulator which allows using an SD card instead of an original hard disk. It can also emulate an original Macintosh Ethernet card, allowing it to fairly easily get online.

The original operating system and browser don’t support modern protocols such as HTTPS or scripting languages like Javascript or CSS, so a tool called MacProxy was used to bridge this gap. It serves simplified HTML from the Internet to the Mac Plus, but [Hunter] wanted it to work even better, adding modular domain-specific handling to allow the computer to more easily access sites like Reddit, YouTube, and even Hackaday, although he does call us out a bit for not maintaining our retro page perhaps as well as it ought to be.

[Hunter] has also built an extension to use the Wayback Machine to serve websites to the Mac from a specific date in the past, which really enhances the retro feel of using a computer like this to access the Internet. Of course, if you don’t have original Macintosh hardware but still want to have the same experience of the early Internet or retro hardware this replica Mac will get you there too.

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Using The 555 For Everything

October 14, 2024 by 26 Comments

The 555 timer is one of the most versatile integrated circuits available. It can generate PWM signals, tones, and single-shot pulses. You can even put one in a bi-stable mode similar to a flip flop. All of these modes are available by only changing a few components outside of the IC itself. It’s also dirt cheap, so it finds its way into all kinds of applications its original inventors never imagined. There’s a bit of a trope around here as well that you ought not to use a microcontroller when one of these will do, and while it’s a bit of a played-out comment, it’s often more true than it seems. This video shows a few uncommon ways of using these circuits instead of putting a microcontroller to work.

After a brief overview of the internals of the hallowed 555, [Doctor Volt] walks us through some of its uses, starting with applications for digital inputs, including a debounce circuit and a toggle switch. From there, he moves on to demonstrating a circuit that can protect batteries from deep discharge, and a small change to that circuit can turn the 555 into a resetting fuse that can protect against short circuit events. Finally, the PWM capabilities of this small integrated circuit are put to work as an audio amplifier, although perhaps not one that would pass muster for the most devout audiophiles among us.

Even though it’s possible to offload a lot of the capabilities of a 555 onto a microcontroller, there’s certainly an opportunity to offload some things to the 555, even if your project still needs a microcontroller. However, offloading tasks like debounce or input latching to hardware rather than spending microcontroller cycles or pins can make a project more robust, both from reliability and software points of view. For some other useful circuits, some of which have been forgotten in the modern microcontroller age, it’s worth taking a look at some of these antique circuit books as well. While we are sure the 555 designers hoped it would be a big hit, no one imagined this giant one.

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Quake In 276 KB Of RAM

October 5, 2024 by 19 Comments

Porting the original DOOM to various pieces of esoteric hardware is a rite of passage in some software circles. But in the modern world, we can get better performance than the 386 processor required to run the 1993 shooter for the cost of a dinner at a nice restaurant — with plenty of other embedded systems blowing these original minimum system requirements out of the water.

For a much tougher challenge, a group from Silicon Labs decided to port DOOM‘s successor, Quake, to the Arduino Nano Matter Board platform instead even though this platform has some pretty significant limitations for a game as advanced as Quake.

To begin work on the memory problem, the group began with a port of Quake originally designed for Windows, allowing them to use a modern Windows machine to whittle down the memory usage before moving over to hardware. They do have a flash memory module available as well, but there’s a speed penalty with this type of memory. To improve speed they did what any true gamer would do with their system: overclock the processor. This got them to around 10 frames per second, which is playable, but not particularly enjoyable. The further optimizations to improve the FPS required a much deeper dive which included generating lookup tables instead of relying on computation, optimizing some of the original C programming, coding some functions in assembly, and only refreshing certain sections of the screen when needed.

On a technical level, Quake was a dramatic improvement over DOOM, allowing for things like real-time 3D rendering, polygonal models instead of sprites, and much more intricate level design. As a result, ports of this game tend to rely on much more powerful processors than DOOM ports and this team shows real mastery of their hardware to pull off a build with a system with these limitations. Other Quake ports we’ve seen like this one running on an iPod Classic require a similar level of knowledge of the code and the ability to use assembly language to make optimizations.

Thanks to [Nicola] for the tip!

Drive For Show, Putt For Dough

October 2, 2024 by 2 Comments

Any golfer will attest that the most impressive looking part of the game—long drives—isn’t where the game is won. To really lower one’s handicap the most important skills to develop are in the short game, especially putting. Even a two-inch putt to close out a hole counts the same as the longest drive, so these skills are not only difficult to master but incredibly valuable. To shortcut some of the skill development, though, [Sparks and Code] broke most rules around the design of golf clubs to construct this robotic putter.

The putter’s goal is to help the golfer with some of the finesse required to master the short game. It can vary its striking force by using an electromagnet to lift the club face a certain amount, depending on the distance needed to sink a putt. Two servos lift the electromagnet and club, then when the appropriate height is reached the electromagnet turns off and the club swings down to strike the ball. The two servos can also oppose each other’s direction to help aim the ball as well, allowing the club to strike at an angle rather than straight on. The club also has built-in rangefinding and a computer vision system so it can identify the hole automatically and determine exactly how it should hit the ball. The only thing the user needs to do is press a button on the shaft of the club.

Even the most famous golfers will have problems putting from time to time so, if you’re willing to skirt the rules a bit, the club might be useful to have around. If not, it’s at least a fun project to show off on the golf course to build one’s credibility around other robotics enthusiasts who also happen to be golfers. If you’re looking for something to be more of a coach or aide rather than an outright cheat, though, this golf club helps analyze and perfect your swing instead of doing everything for you.

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