While the world has been racing for higher and higher bit counts for CPUs, there are always those that buck the trend. Consider the venerable Motorola MC14500B, a 1-bit CPU, no kidding. [Usagi Electric] built up a computer based on one of these chips using a breadboard but has since pulled it apart to use the breadboard for other things. So this time, he’s made a permanent version on a PCB and created a simple game to show it off. You can see the result in the video below.
Well, the chip had one bit in the datapath. It did not have any memory, but it did have a way to feed it 4-bit instructions, and, as you might guess, there were 16 possibilities for instructions. The chip was meant to replace industrial controllers where even a PLC might be overkill, and apparently, it did see some use in the real world.
RepRap 3D printers were designed with the ultimate goal of self-replicating machines. The generatively-designed Gen5X printer by [Ric Real] brings the design step of that process closer to reality.
While 5-axis printing is old hat in CNC land, it remains relatively rare in the world of additive manufacturing. Starting with “a set of primitives… and geometric relationships,” [Real] ran the system through multiple generations to arrive at its current design. Since this is a generative design, future variants could look different depending on which parameters you have the computer optimize.
The Gen5X uses the 5 Axis Slicer from DotX for slicing files and runs a RepRap Duet board with Duex expansion. Since the generative algorithm uses parametric inputs, it should be possible to to have a Gen5X generated based on the vitamins you may have already. With how fast AI is evolving, perhaps soon this printer will be able to completely design itself? For now, you’ll have to download the files and try it yourself.
If you want to see some more printers with more than 3-axes, check out the RotBot or Open5X.
With laser cutters and 3D printers in our arsenal as well as the global toy shop of mass-produced parts and single-board computers, building a robotic project has almost never been easier. In times past though, there was more of a challenge, with a computer likely meaning a chunky desktop model and there being no plethora of motors at low prices, a robot arm required more ingenuity. [Marius Taciuc] shares with us an arm he built from the most minimal of parts back in 2003, and it’s a beautiful exercise in creative reuse.
The arm itself uses metal and FR4 for its structure, and borrows extensively from cassette tape mechanisms for motors and gears. The stronger motor for the forearm is a geared unit from a heating system, and to control all this, a relay board is hooked up to a computer’s parallel port. This last assembly is particularly ingenious, having no optocouplers handy he made his own by coupling LEDs to metal can transistors with their lids removed.
The arm was entered in a competition, and he relates a tale with which we’ll all be familiar — at the critical moment, it didn’t work. Fortunately a last-minute accidental covering of the board with a floppy disk solved the problem, as it turned out that enough light was leaking into those home-made optocouplers to trigger them. The prize was won not just on the strength of the arm, but on his explanation of the lessons learned along the way.
Not that long ago, rolling your own printed circuit boards was difficult, time-consuming and expensive. But thanks to an army of cheap, online manufacturing services as well as high-quality free design software, any hobbyist can now make boards to rival those made by pros. A similar shift might be underway when it comes to chip design: affordable manufacturing options and a set of free software tools are slowly bringing custom chips into the realm of hackers and hobbyists. One of those working hard to democratize chip design is Matt Venn, who’s been telling us all about his current big project, called Tiny Tapeout, in his talk at Remoticon 2022.
Matt’s quest to bring IC design to the masses started in 2020, when the first open-source compatible Process Design Kit (PDK) was released to the public. A PDK is a collection of files, normally only available under strict non-disclosure agreements, that describe all the features of a specific chip manufacturing process and enable you to make a design. With this free PDK in hand and a rag-tag collection of free software tools, Matt set out to design his first chip, a VGA clock, which he taped out (released to manufacturing) in July 2020. Continue reading “Supercon 2022: Matt Venn’s Tiny Tapeout Brings Chip Design To The Masses”→
This is the first we’ve heard of Parametric Press — a digital magazine with some deep dives into a variety of subjects (such as particle physics, “big data” and such) that have interactive elements or simulations of various types embedded within each story.
The first one that sprung up in our news feed is a piece by [Omar Shehata] on the humble JPEG image format. In it, he explains the how and why of the JPEG encoding process, allowing the reader to play with the various concepts along the way, in real time, within the browser.
RGB colour-space subsampling doesn’t affect each component to the same degree due to the human eye cone cell response. Also, the chroma components are much less affected than the luminance.
For those not familiar with the format, the first step (which is actually optional) to JPEG encoding is to transform the image from the RGB color space, into a YCbCr (luminance, chrominance) color space. Since the human eye is far more sensitive to luminance (brightness) differences than it is to Cb (chroma relative blueness) and Cr (chroma relative redness) differences, these latter two components can be subsampled by only storing a single value for each, in every 2×2 pixel matrix. JPEG allows other matrix sizes, but 2×2 is the most common.
This sets the scene for the clever bit, that comes next and allows more of that harder-to-perceive chroma information to be discarded. It’s fun to play with the chroma sub-sampling slider and see how the different colours are not equally affected, due to the relative sensitivities of the human eye cone cells.
Next, the three YCbCr components are treated independently to a discrete cosine transform and quantization. This transforms each 8×8 pixel block into 64 discrete spatial frequencies. The JPEG compression level (which you can change) affects how many of the upper-frequency components get discarded, and thus how much of the fine spatial detail gets discarded. This is the main source of JPEG image quality loss. Finally, the compressed blocks are delta encoded, where each subsequent block is coded as the difference from the previous one. Like chroma subsampling, this doesn’t offer any compression on its own but allows the subsequent run-length encoding to be more effective, giving more (lossless) compression. Finally, the whole lot is then Huffman compressed with a unique table stored in the JPEG header. So want to play with JPEGs some more? here’s the GitHub source.
If all of this theoretical stuff is a bit useless to you, perhaps you just want to decode some JPEGs, then here is a speedy library for just that.
In this USB-C series, we’ve covered quite a bit of USB-C – things that are well known, things that should be better known, and a couple things that just appeared online for the first time. We’ve covered almost everything in some depth except USB Power Delivery. I’ve described the process a bit in the “Power” article, but that was mostly about how to use PD by simply buying the right solution. However, that’s not enough for a hacker. Let’s see if we can make our own PD trigger board. Continue reading “All About USB-C: Talking Low-Level PD”→
What do you do when you have a lot of LiDAR data and not enough budget to slog through it? That’s the problem the Heritage Quest project was faced with — they had 600,000 LiDAR maps in the Netherlands and wanted to find burial mounds using the data. By harnessing 6,500 citizen scientists, they were able to analyze the data and locate over 1,000 prehistoric burial mounds, including many that were previously unknown, along with cart tracks, kilns, and other items of archaeological interest.
The project used Zooniverse, a site we’ve mentioned before, to help train volunteers to analyze data. The project had at least 15 volunteers examining each map. The sites date between 2,800 and 500 BC. Archaeologists spent the summer of 2021 verifying many of these digital finds. They took samples from 300 sites and determined that 80 of them were previously unknown. They estimate that the total number of sites found by the volunteers could be as high as 1,250.
This is a great example of how modern technology is changing many fields and the power of citizen science, both topics we always want to hear more about. We’ve seen NASA tapping citizen scientists, and we’ve even seen high school students building research buoys. So if you’ve ever wanted to participate in advancing the world’s scientific knowledge, there’s never been a better time to do it.
