Perler Printer Pushes Pixel-Art like No Sprite Artist Could
By Joshua Vasquez
There’s something oddly soothing about the practice of laying down Perler Beads on a casual weekend to make your favorite classic Nintendo characters. But seriously, why use our grubby hands like a caveman when we could leverage a machine to do the heavy-lifting for us? That’s exactly what [knezuld11] did! They’ve built a 64-color Bead Sprite Printer including an automatic cooking feature for fusing the result. (Video, embedded below.)
From the top, up to 64 unique bead colors are stashed into cartridges at the top. A bulk agitator does the work of passing these beads into tubes for the lower-stage bead selector. At this level, beads colors are serialized into a single tube that feeds into the output “nozzle.” The entire process of directing the bead pattern is driven by a Python script that takes images as input and approximates their colors to the available bead palette. When the bead “printing” is done, the machine ramps up its heated bed and cooks the bottoms of the beads, fusing them together in a way that [knezuld11] says works actually better than the typical ironing method.
We simply love how feature-complete this system is. While [knezuld11] mentioned that the Bead Sprite Printer was an attempt at beating a world record, we imagine that there are dozens of other ways this machine could lead to some whimsical engagements. Quite frankly, we’d love to see this machine at an Artist Alley making on-demand art.
If you managed to spill all your beads from sheer excitement watching this video, fret not! This automatic bead sorter from our past is just the thing to help you out.
Big Beautiful Vintage Computers, and Where To Find Them
By Donald Papp
[Ken Shirriff] recently shared some pictures and a writeup from his visit to the Large Scale Systems Museum, a remarkable private collection of mainframes and other computers from the 1970s to the 1990s. Housed in a town outside Pittsburgh, it contains a huge variety of specimens including IBM mainframes and desk-sized minicomputers, enormous disk and tape storage systems, and multiple 90s-era Cray supercomputers. It doesn’t stop there, either. Everything through the minicomputer revolution leading to personal home computers is present, and there are even several Heathkit HERO robot kits from the 80s. (By the way, we once saw a HERO retrofitted with wireless and the ability to run Python.)
Something really special is that many of the vintage systems are in working order, providing insight into how these units performed and acted. The museum is a private collection and is open only by appointment but they encourage interested parties not to be shy. If a trip to the museum isn’t for you, [Ken] has some additional photos from his visit here for you to check out.
The Future’s So Bright, I Gotta Wear LCDs
By Tom Nardi
Whether it was rays from the Sun that made a 150 million kilometer trip just to ruin your day or somebody’s unreasonably bright aftermarket headlights, at some point or another we’ve all experienced the discomfort of bright spots in our eyes. But short of wearing welder’s goggles all the time, what can we do? Luckily for us, [Nick Bild] has come up with a solution. Sort of.
By adding LCDs to a pair of standard sunglasses, [Nick] has created something he’s calling “Light Brakes”. The idea is that the LCDs, having their backings removed, can essentially be used as programmable shutters to block out a specific part of the image that’s passing through them. With the addition of a Raspberry Pi and a camera, the Light Brakes can identify an unusually bright source of light and block it from the wearer’s vision by drawing a sufficiently large blob on the LCDs.
At least, that’s the idea. As you can see in the video after the break, the LCDs ability to block out a moving source of light is somewhat debatable. It’s also unclear what, if any, effect the “blocking” would have on UV, so you definitely shouldn’t try looking at the sun with a pair of these.
That said, a refined version of the concept could have some very interesting applications. For instance, imagine a pair of glasses that could actively block out advertisements or other unpleasant images from your field of vision. If this all sounds a bit like something out of an episode of Black Mirror, that’s because it is.
The concept here is fairly simple: there’s a text file in /boot that contains the truncated names of all the talks and workshops in the schedule, one per line, and each line starts with the time that particular event is scheduled for. The script that [vgrsec] wrote opens this text file, searches for the lines beginning with the current time, and generates the appropriate SSIDs. With the number of tracks being run at DerbyCon, that meant there could be as many as five SSIDs generated at once.
Now in theory that would be enough to pull off this particular hack, but there’s a problem. The lack of an RTC on the Raspberry Pi means it can’t keep time very well, and the fact that the WiFi adapter would be busy pumping out SSIDs meant the chances of it being able to connect to the Internet and pull down the current time over NTP weren’t very good.
As the system was worthless without a reliable way of keeping time, [vgrsec] added an Adafruit PiRTC module to the mix. Once the time has been synchronized, the system could then run untethered via a USB battery bank. We might have put it into an enclosure so it looks a little less suspect, but then again, there were certainly far more unusual devices than this to be seen at DerbyCon.
Of course, if you’re OK with just dumping the entire schedule out at once and letting the user sift through the mountain of bogus SSIDs themselves, that’s even easier to accomplish.
Steering By Touch And Haptic Feedback
By Sharon Lin
Scribble is a haptic interface lets you draw your way through traffic. In an environment where fully automated vehicles are becoming the expectation for the next step in transportation, Scribble provides a friendly alternative that allows you to guide your car around, while the automation makes decisions on how to actually steer the car around obstacles.
The driver is guided by haptic feedback that alerts them about the road conditions or obstacles ahead. The project was conceived by [Felix Ros] for his master’s thesis at Eindhoven University, featured a five bar linkage that moves with two lateral degrees of freedom, commonly used for drawing robots.
The code run on an Arduino DUE control over serial by a program made in Open Frameworks that communicates with a Unity 3D driving simulator over UDP. Fellow graduate student [Frank van Valeknhoef]’s Haptic Engines are used as the actuators, outputting the position and a variable force.
The forward kinematics algorithms were based on a clock and weather plotter by SAP, sharing the same servo and drawing arm assembly. The left and right actuators update based on the desired angle, calculating the proper angles needed to achieve the correct position.
While automated vehicles may be able to travel efficiently from one destination to the next, they can’t necessarily wander off course to explore new places. Scribble takes back some of that freedom and allows drivers to decide for themselves where they want to be. It’s an interesting take at inserting the human back into the driver’s seat in automated cars.
A Miniature Radio Telescope in Every Backyard
By Tom Nardi
You probably wouldn’t expect to see somebody making astronomical observations during a cloudy day in the center of a dense urban area, but that’s exactly what was happening at the recent 2019 Philadelphia Mini Maker Faire. Professor James Aguirre of the University of Pennsylvania was there demonstrating the particularly compact Mini Radio Telescope (MRT) project built around an old DirecTV satellite dish and a smattering of low-cost components, giving visitors a view of the sky in a way most had never seen before.
Thanks to the project’s extensive online documentation, anyone with a spare satellite dish and a couple hundred dollars in support hardware can build their very own personal radio telescope that’s capable of observing objects in the sky no matter what the time of day or weather conditions are. Even if you’re not interested in peering into deep space from the comfort of your own home, the MRT offers a framework for building an automatic pan-and-tilt directional antenna platform that could be used for picking up signals from orbiting satellites.
With the slow collapse of satellite television in the United States these dishes are often free for the taking, and a fairly common sight on the sidewalk come garbage day. Perhaps there’s even one (or three) sitting on your own roof as you read this, waiting for a new lease on life in the Netflix Era.
Whether it’s to satisfy your own curiosity or because you want to follow in Professor Aguirre’s footsteps and use it as a tool for STEM outreach, projects like MRT make it easier than ever to build a functional DIY radio telescope.
Point and Shoot
The MRT, and really any radio telescope project like this, is essentially made up of two separate systems: one that provides the motorized aiming of the dish, and the receiver that actually captures the signals. Either system could work independently of the other, but when combined with the appropriate software “glue”, they allow the user to map the sky in radio frequencies.
Obviously, the electronics and mechanical components required to pan an antenna across the sky aren’t terribly complex. If you wanted to keep things really simple and were content with moving in a single axis, you could even do it with a “barn door” tracker. What’s really kicked off the recent explosion of DIY radio telescopes is the RTL-SDR project and the era of low-cost Software Defined Radios (SDRs) it’s inspired.
Unsurprisingly, the MRT also uses an RTL-SDR receiver for processing signals from the Low-Noise Block (LNB) in the dish. Professor Aguirre says that since they are still using the stock DirecTV LNB, the telescope is fairly limited in what it can actually “see”. But it’s good enough to image the sun or pick up satellites in orbit, which is sufficient for the purposes of demonstrating the basic operating principles of a radio telescope.
To move the satellite dish, the MRT is using an Arduino connected to a trio of Big Easy Drivers from Sparkfun. These are in turn connected to the stepper motors in the antenna mount, which are sufficiently geared so they can move the dish around without the need for a counterweight. This makes it an excellent candidate for enclosure inside a dome, which would allow for all-weather observations.
Both the RTL-SDR receiver and the Arduino are connected to a Raspberry Pi, which runs the software for the telescope and provides the interface for the user. The MRT GitHub repository contains all of the various tools and programs created for the project, mostly written in Python, which should provide a useful reference even if you’re not interested in duplicating the telescope’s overall design.
Wandering Through the Sky
When we visited Professor Aguirre, he was attempting to use the MRT to find the Sun. You’d think that a simple enough task in the middle of the afternoon, but thanks to an unbroken layer of steel-gray clouds hanging low in the October sky, Sol was absolutely nowhere to be found with our meager human senses.
As the dish made its slow robotic pans across the sky, we spoke with the Professor about the telescope and the various revisions it went through over the years. Eventually the display lit up, showing a representation of an unusually strong signal, clearly the MRT was hearing something out there. After brief scrutiny, the Professor announced that we hadn’t found the sun; instead, the telescope most likely crossed paths with a geostationary satellite.
It was this raconteur style of discovery that kept visitors to the Mini Radio Telescope enthralled. Nobody expected this hacked together contraption of consumer-grade hardware to discover a new exoplanet or help solve some long-pondered mystery of the cosmos while sitting in a Philadelphia parking lot.
But it was more than capable of pointing out objects tens of thousands of kilometers away while our own eyes couldn’t even figure out where the Sun was. It reaffirmed in a very real way that something was out there, and students both young and old couldn’t help but be fascinated by it.
The project currently uses a Beaglebone for the brains, with a polygon motor sourced from a photocopier used to rotate the prism at over 20,000 rpm. The project aims to be a proof of concept for rotating prism technology, which can then be adapted to specific tasks. With the promise of high speed and high resolution, the system could be used in fields as diverse as PCB manufacture, 3D resin printing, and even virtual reality displays. [Rick] explores these potential markets in a pitch deck, comparing to existing solutions in the marketplace.