It might take you some time to understand what’s happening in the video that Hackaday alum [Moritz Sivers] shared with us. This is [Moritz]’s contribution for this year’s Pi Day – a machine that shows digits of Pi in a (technically, not quite) infinite loop, and shows us a neat trick we wouldn’t have thought of.
The two main elements of this machine are a looped piece of thermochromic foil and a thermal printer. As digits are marked on the foil by the printer’s heating element, they’re visible for a few seconds until the foil disappears from the view, only to be eventually looped back and thermally embossed anew. The “Pi digits calculation” part is offloaded to Google’s pi.delivery service, a π-as-a-Service endpoint that will stream up to 50 trillion first digits of Pi in case you ever need them – an ESP8266 dutifully fetches the digits and sends them off to the thermal printer.
This machine could print the digits until something breaks or the trillions of digits available run out, and is an appropriate tribute to the infinite nature of Pi, a number we all have no choice but to fundamentally respect. A few days ago, we’ve shown a similar Pi Day tribute, albeit a more self-sufficient one – an Arduino calculating and printing digits of Pi on a character display! We could’ve been celebrating this day for millennia, if Archimedes could just count a little better.
Sometimes there are projects that we introduce with a bit of context, some background, and other times as with [RayP2]’s fractal papercraft tree, we introduce them simply because they are beautiful.
It’s a deceptively simple design of a repeating pattern of the same shape getting ever smaller with each iteration, and terminating in a tetrahedron with branches from each of its faces. It’s not origami, instead it’s a cut-and-glue design, and its construction is a surprisingly involved affair with some lateral thinking required to bend the tabs on the smaller branches. The design was first prototyped with plain paper, before a final version was made with card stock. The part that makes it exceptional is that he used shiny gold card stock with the gold side on the inside, meaning that when lit from the trunk the end of each branch glows attractively. Fitting the light required a modification to the trunk design, but this doesn’t take away from the whole.
The result is an attractive sculpture, a talking point, and something with a mathematical angle to boot, which we like. It’s certainly not been the first papercraft ptoject we’ve shown you, though perhaps these paper retrocomputers are a little less artistic.
Like many of us, [Paul] enjoys occasionally hitching up his tow-behind camper and heading out to the wilderness to get away from it all at his favorite campsite. Unlike the vast majority of those who share his passion for the outdoors, though, [Paul] is hitching his camper up to a bicycle. Both the camper and the bike are custom built from the ground up, and this video shows us a little more details on [Paul]’s preferred mode of transportation.
While he is known for building custom vehicles of one sort or another, this latest one is a more traditional bicycle frame that he has modified only slightly to fit a recumbent-style seat and a small gas-powered motor. Even though the motor is decades old, it started right up and gives the power needed to pull the custom camper. [Paul] builds one-person campers like this out of corrugated plastic for durability and light weight, and this one is specifically designed for his size and sleeping style. It includes everything needed for a night under the stars, too, including a stove, storage compartments, and a few windows.
With the bike and camper combined weighing in at just over 200 pounds, the motor can be used as a pedal-assist device thanks to the clever engineering behind a front-wheel-drive pedal system on this bike. With all of that custom fabrication, [Paul] is free to head out to the wilderness without all the encumbrances (and high price) of traditional motor vehicle-based camping. For those curious about some of [Paul]’s other vehicle creations, take a look at this tiny speedboat for one.
Well, that de-escalated quickly! It was less than a week ago that the city of Shenzhen, China was put on lockdown due to a resurgence of COVID-19 in the world’s electronics manufacturing epicenter. This obviously caused no small amount of alarm up and down the electronics supply chain, promising to once again upset manufacturers seeking everything from PCBs to components to complete electronic assemblies. But just a few days later, the Chinese government announced that the Shenzhen lockdown was over. At least partially, that is — factories and public transportation have been reopened in five of the city’s districts, with iPhone maker Foxconn, one of the bigger players in Shenzhen, given the green light to partially reopen. What does this mean for hobbyists’ ability to get cheap PCBs made quickly? That’s hard to say, at least at this point. Please feel free to share your experiences with any supply chain disruptions in the comments below.
Better news from a million miles away, as NASA announced that the James Webb Space Telescope finished the first part of its complex mirror alignment procedure. The process, which uses the complex actuators built into each of the 18 hexagonal mirror segments, slightly moves each mirror to align them all into one virtual optical surface. The result is not only the stunning “selfie” images we’ve been seeing, but also a beautiful picture of the star Webb has been focusing on as a target. The video below explains the process in some detail, along with sharing that the next step is to move the mirrors in and out, or “piston” them, so that the 18 separate wavefronts all align to send light to the instruments in perfect phase. Talk about precision!
Is a bog-standard Raspberry Pi just not tough enough for your application? Do you need to run DOOM on a platform that can take a few g of vibration and still keep working? Sick of your Pi-based weather station breaking own when it gets a little wet or too hot? Then you’ll want to take a look at the DuraCOR Pi, a ruggedized chassis containing a Pi CM4 that’s built for extreme environments. The machine is in a tiny IP67-rated case and built to MIL-STD specs with regard to vibration, temperature, humidity, and EMI conditions. This doesn’t really seem like something aimed at the hobbyist market — it’s marketed by Curtiss-Wright Defense Solutions, a defense contractor that traces its roots all the way back to a couple of bicycle mechanics from Ohio that learned how to fly. So this Pi is probably more like something you’d spec if you were building a UAV or something like that. Still, it’s cool to know such things are out there.
BrainLubeOnline has a fun collection of X-rays. With the exception of a mouse — the other kind — everything is either electronic or mechanical, which makes for really interesting pictures. Seeing the teeth on a gear or the threads on a screw, and seeing right through the object, shows the mechanical world in a whole new light — literally.
And finally, would you buy a car that prevents you from opening the hood? Most of us probably wouldn’t, but then again, most of us probably wouldn’t buy a Mercedes EQS 580 electric sedan. Sarah from Sarah -n- Tuned on YouTube somehow got a hold of one of these babies, which she aptly describes as a “German spaceship,” and took it for a test drive, including a “full beans” acceleration test. Just after that neck-snapping ride, at about the 7:20 mark in the video below, she asks the car’s built-in assistant to open the hood, a request the car refused by saying, “The hood may only be opened by a specialist workshop.” Sarah managed to get it open anyway, and it’s not a frunk — it’s home to one of the two motors that power the car, along with all kinds of other goodies.
[Peng Zhihui] seems to have found some spare time and energy to crack out another sweet robot build, this time it’s a much smaller, and cuter emoji-bot (Original GitHub Link,) with the usual production-ready levels of attention to detail. With a lot of fine details in the 3D printed models, this is one for SLS printing in nylon, but that can be done for a reasonable outlay, in China at least. The electronics package consists of a few full custom, and tiny, PCBs designed with Altium Designer, with off-the-shelf modules for the circular LCD and camera. The main board hosts an STM32F405 and deals with the display and SD card, The reason for this choice of STM32 was due to the requirement for connecting to an external USB3300 high-speed USB PHY. There is a sensor PCB which handles the gesture sensor, a USB hub, MPU6050 9-axis sensor, and also the USB camera module. This board attaches to the USB-C connector in the base, via a FFC cable, allowing the robot to rotate on its base.
Cunning two-servo shoulder mechanism
[Peng] clearly has exacting standards as to how things should work, and we guess wanted to have the arms back-driveable in a way that enabled the host computer to track and record the motor positions for replaying later on. The connection back to the controller is via I2C, allowing all five servos to hang on the same bus, saving previous resources. Smart! Getting a processor and motor driver in such a tiny space was a bit of challenge, but a walk in the park for [Peng] as is demonstrates in the video embedded below (We believe English subtitles are pending!) The arm mechanism is particularly interesting, and rather elegantly executed, and he does seem rather proud of this part of the design, and so he should! Like with [Peng’s] other projects, there is a lot to see, and plenty of scope for feature explosion. It was nice to see the ‘bot being used as an input device, not only with gesture sensing via the dedicated sensor, but also using the camera with OpenCV to track user posture and act accordingly. This thing could act as genuinely useful AI device, as was a being darn cute at the same time!
Keeping tabs on the night sky is an enjoyable way to stay connected to the stars, and astronomy can be accessible to most people with a low entry point for DIY telescopes. For those who live in areas with too much light pollution, though, cost is not the only issue facing amateur astronomers. Luckily there are more ways to observe the night sky, like with this open source software package from [elanorlutz] which keeps tabs on all known asteroids.
The software is largely based on Python and uses a number of databases from NASA to allow anyone with a computer to explore various maps of the solar system and the planetary and non-planetary bodies within it. Various trajectories can be calculated, and paths of other solar system bodies can be shown with respect to an observer in various locations. Once the calculations are made in Python it is able to export the images for use in whichever image manipulation software you prefer.
The classic arcade game Cyclone has attracted many players, along with their coins, thanks to its simple yet addictive gameplay. In its most basic form it consists of a light racing around a circular track, which the player then has to stop at exactly the right place. Arduino enthusiast [mircemk] made a home version of this game, which allows addicts to keep playing forever without running out of quarters.
Instead of an arcade cabinet, this smaller version has an upright 3D-printed ring that holds 60 WS2812 LEDs. A further six in the center of the ring act as a score counter. An Arduino in the base drives the LEDs and runs the game, which is based on an earlier iteration built by [oKeeg]. An interesting addition is a large homemade “arcade button”, which is large and sturdy enough to withstand any abuse inflicted on it by a frustrated player.
