Its safe to say that colour television is taken for granted nowadays. Consumed by the modern marketing jargon of colour dynamic range, colour space accuracy and depth, it is easy to overlook the humble beginnings of image reproduction when simply reconstructing an image with the slightest hint of colour required some serious ingenuity and earned you a well deserved pat on the back!
[anfractuosus] revisited an old gem of a technique, first patented in 1903 and used it to successful make an old monochrome TV produce a colour image. The idea in essence, is actually similar to what cheap image sensors and LCDs still use today. Rather than relying on true RGB colour generation by individually integrating colour sources as AMOLED does, we take an easier route: Produce a simpler monochrome image where each colour pixel is physically represented by four monochrome sub-pixels, one for each colour component. Now light up each of the sub-pixels according to the colour information of your image and rely on an external colour filter array to combine and spit out the correct colours.
He first used some image processing to convert a standard colour video into the aforementioned monochrome sub-pixel representation. Next, a Bayer colour filter array was printed on some acetate sheets using an inkjet printer (the original inventors used potato starch!), which when overlaid on top of the monochrome monitor, magically result in colour output.
There are some problems associated with this technique, mainly to do with the difficulty in measuring the size of the TV pixels and then producing and perfectly aligning a filter sheet for it. You should check out how [anfractuosus] went about solving those issues.
So now you know a bit more about colour image generation, but how about colour TV transmission? Check out an earlier piece to learn more.
There’s no denying that the reach and variety of internet radio is super cool. The problem is that none of the available interfaces really give the enormity of the thing the justice it deserves. We long for a more physical and satisfying interface for tuning in stations from around the globe, and [Jude] has made just the thing.
The other encoder is on the left side of the globe, and reads whatever latitude is focused in the reticle. Both encoder are connected to a Raspberry Pi 4, though if you want to replicate this open-source project using the incredibly detailed instructions, he says a Raspberry Pi 3 B+ will work, too.
In the base there’s an LCD that shows the coordinates, the city, and the station ID. Other stations in the area are tune-able with the jog wheel on the base. There’s also an RGB LED that blinks red while the station is being tuned in, and turns green when it’s done. We totally dig the clean and minimalist look of this build — especially the surprise transparent bottom panel that lets you see all the guts.
There are three videos after the break – a short demo that gives you the gist of how it works, a longer demonstration, and a nice explanation of absolute rotary encoders. Those are just the tip of the iceberg, because [Jude] kept a daily vlog of the build.
If 2020 can be remembered in any positive light, it would be that this has been the year of the hobby tryouts. Why not pottery? Sure, throwing pots won’t fill your belly like homemade bread. But we would bet you can see the value in having a bunch of expendable objects that are easily (and quite satisfyingly) smashed to smithereens. The best part is that between the workbench, junk box, and recycle bin, you can probably build [Jadem52]’s pottery wheel for ants with stuff you already have. Bonus!
Pottery wheels aren’t that complicated. They’re honestly kind of expensive for what they are — a motor and a belt driving a rotating platter. It’s like a record player, but less fussy. Where they really get you on expense is the kiln to heat-treat those pots into sturdy vessels. But you could always use air-dry clay, especially if you’re making these things just to smash them whenever you need to let off some steam.
So anyway, you don’t need much more than a motor, a jar lid for a wheel to throw on, and a bearing to make it spin smoothly. Store-bought pottery wheels have a foot feed to control the motor speed, but this pocket version is either spinning on nine volts or it isn’t. The great thing about a project like this is that once you have the general principle down and use the thing, you can iterate and upgrade to your heart’s content. Take it for a little spin after the break.
The drive train of this bicycle starts with a brushless DC motor from a washing machine. It has been slightly modified to run on 48 volts, and is installed inside the triangle of the bike’s frame. It has a chain driving the bike’s crank, retaining the original chain and gearing setup (unlike many electric bike hacks that utilize hub motors). The crank has also been specially modified to include a freewheel, a necessary feature so that the motor can operate without spinning the pedals. Everything except the motor has been custom fabricated including the mounts and the electronics.
[jimminecraftguy] reports speeds of 110 kph which is a little crazy for a 20-year-old aluminum frame bike, and we’d guess it’s not street legal in many jurisdictions, but we can’t really find much fault with this build in general based on the amount of innovation required to get this working at all. A few more improvements for the build are in the works, including improved batteries and a cover for the sides to keep the local law enforcement from getting too suspicious. We can’t wait to see the final version. Continue reading “The Spin Cycle: Washing Machine Motor Converts 10-Speed To E-Bike”→
We all have our own preferences when it comes to travel souvenirs — that little something that brings back the memories and feelings of a past holiday every time we look at it, whether it’s the cliché fridge magnet, some local speciality, or just the collection of photos we took. But then there are those journeys that can’t be summarized into a single item and may require a bit more creativity. For [Jonathan], it was last year’s trip around the world that took him and [Maria] to locations all over Europe, Asia, and Oceania, and he found a great way to remember it: an interactive, laser-cut travel globe displaying all the places they went to.
Building a sphere is of course a bit tricky with a laser cutter, so [Jonathan] went for the icosahedron shaped Dymaxion map projection (think of a large d20 dice) and burnt the world onto it. Inside the globe is an ESP8266, an MPU-6050 IMU, and a bunch of LEDs to light up the travel locations using the WLED library. Taking the data from the IMU, he customized the WLED library to determine which way the globe is positioned, and highlights the top-facing location in a different color.
While that would already make a nice souvenir on its own, [Jonathan] didn’t stop here. Using Google’s My Maps service, which lets you create custom maps with own points of interest and have for example photos attached to them, the ESP8266 hosts the travel map also as a web page. Feeding the IMU data to the JavaScript code that’s handling the map API, the globe itself now doubles as an input device to control the virtual map. So whenever the globe is physically rotated to highlight a certain location, the web page’s map is focused to that same location and shows randomly the pictures they have taken there. Check out the video below to see it all in action.
This is a great way to reminisce about a memorable journey even years down the road, and while it may not be flexible to extend, it seems like the kind of trip that deserves a standalone device anyway. Plus, the Dymaxion map is definitely an interesting projection — so here’a a foldable one, just because. And If you like tracking things on a globe, here’s one that shows the location of the ISS.
This morning the Open Source Hardware Association (OSHWA) announced a resolution for changing the way SPI (Serial Peripheral Interface) pins are labelled on hardware and in datasheets. The protocol originally included MOSI/MISO references that stand for “Master Out, Slave In” and “Master In, Slave Out”. Some companies and individuals have stopped using these terms over the years, but an effort is being taken up to affect widespread change, lead by Nathan Seidle of Sparkfun.
The new language for SPI pin labeling recommends the use of SDO/SDI (Serial Data Out/In) for single-role hardware, and COPI/CIPO for “Controller Out, Peripheral In” and “Controller In, Peripheral Out” for devices that can be either the controller or the peripheral. The change also updates the “SS” (Slave Select) pin to use “CS” (Chip Select).
SPI is widely used in embedded system design and appears in a huge range of devices, with the pin labels published numerous times in everything from datasheets and application notes to written and video tutorials posted online. Changing the labels removes unnecessary references to slavery without affecting the technology itself. This move makes embedded engineering more inclusive, an ideal that’s easy to get behind.
[2022 Editor’s Note: The OSHWA changed its recommended naming to PICO/POCI for “Peripheral In, Controller Out” and “Peripheral Out, Controller In”. Fine by us! I’ve updated this throughout the rest of the article because it doesn’t change Mike’s original argument at all.]
So after a false start due to bad weather, the first crewed launch of a SpaceX Crew Dragon capsule with two astronauts on board has gone ahead. After playing catch-up with the ISS for around 27 hours they’re now safely aboard. At times it seems that space launches have become everyday occurrences, but they are still heroes who have risked their lives in the furtherment of mankind’s exploration of space. Their achievement, and that of all the scientists, engineers, and other staff who stand behind them, is immense.
I watched the drama unfold via the live video feed. Having heaved a huge sigh of relief once they were safely in orbit, the feed cut to the studio, and then moved on to interview the NASA administrator Jim Bridenstine. He was naturally elated at a successful launch, and enthused about the agency’s achievement. You can watch the full interview embedded below, but what caught my attention was his parting sentence:
And if this can inspire a young child to become the next Elon Musk, or the next Jeff Bezos, or the next Sir Richard Branson, then that’s what this is all about
I was slightly shocked and saddened to hear this from the NASA administrator, because to my mind the careers of Musk, Bezos, or Branson should not be the ones first brought to mind by a space launch. This isn’t a comment on those three in themselves; although they have many critics it is undeniable that they have each through their respective space companies brought much to the world of space flight. Instead it’s a comment on what a NASA administrator should be trying to inspire in kids.
Ask yourself how many billionaire masters-of-the-universe it takes for a successful space race compared to the number of scientists, engineers, mathematicians, technicians, physicists, et al. From the anecdote of the NASA administrator it takes about three, but if he is to make good on his goal of returning to the Moon in 2024 and then eventually taking humanity to Mars it will take a generation packed full of those other roles. To understand that we’ll have to take a trip back to the Apollo era, and how that generation of kids were inspired by the spacecraft on their screens.
Inspiration from probably the coolest room in the world at the time, the Apollo mission control in Houston. NASA on The Commons / No restrictions
Fifty years ago, we were very much on the brink of becoming a spacefaring planet. American astronauts were taking their first steps on the Moon, and Soviet cosmonauts were occupying real space stations that would soon be capable of housing them for months at a time. Planetary probes were returning colour TV pictures from other worlds, and it was certain that in the immediate aftermath of the Apollo programme we’d be sending astronauts and probably cosmonauts too further afield. A Mars base in the 1980s perhaps, and following our fictional Star Trek heroes further afield thereafter.
We now know it didn’t quite work out that way, but a whole generation of tech-inclined kids grew up wanting nothing more than to be involved in space flight. The vast majority of us never made it, but with that inspiration we took our soldering irons and 8-bit home computers and ran with them. Those NASA folks were the coolest of role-models, and no doubt their Soviet equivalents were too for kids on the other side of the Iron Curtain.
With the best will in the world, the chances of any kid becoming the next Jeff Bezos is about as high as that of their becoming the next Neil Armstrong. Compared to the number of kids in the world, the number of billionaires and the number of astronauts both pale into statistical insignificance. But the chances of a kid becoming an engineer or a scientist is much higher, and in those careers their chances of having some of their work be involved with the space effort becomes not entirely unlikely.
I understand what the NASA administrator was trying to say, but can’t shake the feeling that if those are the people he rolls out to inspire kids watching a space launch, he’s missed an opportunity. Those are the names we all recognize, but shouldn’t we also elevate the people making the scientific breakthroughs so their names are equally recognized? Like Margaret Hamilton, Gene Kranz, and Sergei Korolev and many others before them, we should be making names like Tom Mueller and Margarita Marinova prominent examples of where a career in the sciences can take you. But to be honest, the real problem is we just don’t hear much about all the people doing this fascinating engineering and that’s a sad state of affairs.
Looks like it’s time for Hackaday to pursue a biography series based on the many great minds who are the ones delivering on the promise and vision of today’s (and tomorrow’s) space race. Get us started by talking about your favorite behind the scenes science folks in the comments below.
