At the heart of all computers is a clock, a dedicated timepiece ensuring that all of the parts of the computer are synchronized and can work together to execute the instructions that the computer receives. Clock speeds for most modern off-the-shelf computers and smartphones operate around a billion cycles per second, and even clocks that tick at a human-dizzying speed of a million times per second have been around since at least the 1970s. But there’s no reason a computer can’t run at a much slower speed, as [Greg] demonstrates in this video where he slows down a 6502 processor to a single clock cycle per second.
To reduce the clock speed from the megahertz range down to a single hertz or single clock cycle per second, [Greg] is using the pendulum from an actual clock. He attaches a small magnet to the bottom of the pendulum which is counted by a sensor as it swings past. Feeding that pulse into a monostable conditioner yields a clock signal which is usable for one of his 6502-based computers, and at this extremely slow rate, it’s possible to see the operation of a lot of the computers’ inner workings a step at a time. In fact, he optimized the computer’s operation as this slow speed let him see some inefficiencies in the program he was running.
It helps if your processor is static, of course. Older CPUs with dynamic storage for registers and some with limited-range PLLs would not work with this technique. The 8080A, for example, required a clock of at least 500 kHz.
Not only can this computer use a pendulum clock as the basis for its internal clock, but [Greg] also rigged up a mechanism to use a heartbeat. Getting in a little bit of exercise to increase his heart rate first will noticeably increase the computer’s speed. And, if you’re looking to get a deeper glimpse into the inner workings of a computer, we’d recommend looking at one which forgoes transistors in favor of relays.
Solar panels are a great way to generate clean electricity, but require some energy storage mechanism if you also want to use their power at night. This can be a bit tricky for large solar farms that feed into the grid, which require enormous battery banks or pumped storage systems to capture a reasonable amount of energy. It’s much easier for small, handheld solar gadgets, which work just fine with a small rechargeable battery or even a big capacitor. [Jamie Matthews], for instance, built a loudspeaker that runs on solar power but can also work in the dark thanks to two supercapacitors.
The speaker’s 3D-printed case has a 60 x 90 mm2 solar panel mounted at the front, which charges a pair of 400 Farad supercaps. Audio input is either through a classic 3.5 mm socket or through the analog audio feature of a USB-C socket. That same USB port can also be used to directly charge the supercaps when no sunlight is available, or to attach a Bluetooth audio receiver, which in that case will be powered by the speaker.
The speaker’s outer shell, the front bezel, and even the passive radiator are 3D-printed and spray-painted. The radiator is made of a center cap that is weighed down by a couple of M4 screws and suspended in a flexible membrane. [Jamie] used glue on all openings to ensure the box remains nearly airtight, which is required for the passive radiator to work properly. Speaker fabric is used to cover the front, including the solar panel – it’s apparently transparent enough to let a few watts of solar power through.
A salvaged three-inch Bose driver is the actual audio source. It’s driven by a TI TPA2013D1 chip, which is a 2.7 W class-D amplifier with an integrated boost converter. This enables the chip to keep a constant output power level across a wide supply voltage range – ideal for supercapacitor operation since supercaps don’t keep a constant voltage like lithium batteries do.
[Jamie] has used the speaker for more than nine months so far and has only had to charge it twice manually. It probably helps that he lives in sunny South Africa, but we’ve seen similar solar audio projects work just fine in places like Denmark. If you’re taking your boombox to the beach, a sunscreen reminder feature might also come in handy.
Snooping in on satellites is getting to be quite popular, enough so that the number of people advancing the state of the art — not to mention the wealth of satellites transmitting signals in the clear — has almost made the hobby too easy. An SDR, a homebrew antenna, and some off-the-shelf software, and you too can see weather satellite images on your screen in real time.
But where’s the challenge? That seems to be the question [dereksgc] asked and answered by tapping into S-band telemetry from an obsolete satellite. Most satellite hunters focus on downlinks in the L-band or even the VHF portion of the spectrum, which are within easy reach of most RTL-SDR dongles. However, the Coriolis satellite, which was launched in 2003, has a downlink firmly in the S-band, which at 2.2-GHz puts it just outside the high end of an RTL-SDR. To work around this, [dereksgc] bought a knock-off HackRF SDR and couple it with a wideband low-noise amplifier (LNA) of his own design. The dish antenna is also homebrewed from a used 1.8-m dish and a custom helical antenna for the right-hand circular polarized downlink signal.
As the video below shows, receiving downlink signals from Coriolis with the rig wasn’t all that difficult. Even with manually steering the dish, [dereksgc] was able to record a couple of decent passes with SDR#. Making sense of the data from WINDSAT, a passive microwave polarimetric radiometer that’s the main instrument that’s still working on the satellite, was another matter. Decoded with SatDump and massaged with Gimp, the microwave images of Europe are at least recognizable, mostly due to Italy’s distinctive shape.
Despite the distortion, seeing the planet’s surface via the microwaves emitted by water vapor is still pretty cool. If more traditional weather satellite images are what you’re looking for, those are pretty cool too.
Being mute or speech-challenged can be a barrier, and [Raymond Li] has an interesting project to contribute to the 2023 Hackaday Prize: a pair of discreet chording keyboards that allow the user to emit live text-to-speech as quickly as one can manipulate them.
The project leverages recent developments to deliver high-quality speech via an open-source web app called VoiceBox, while making sure the input devices themselves don’t get in the way of personal interaction. Keeping the chorders at waist level and ensuring high-quality speech is generated and delivered quickly goes a long way towards making interaction and communication flow more naturally.
The VoiceBox software is doing the heavy lifting, and there’s not yet much detail about the rest of the hardware used in the prototype. It’s currently up to the user to figure out a solution for a wearable computer or a suitable chording keyboard. Still, the prototype looks like the Charachorder with a 3D-printed mounting solution to locate them at one’s beltline. Of course, the beauty of the underlying system being so standard is that one can use whatever is most comfortable.
It’s been a distressing trend over the last decade, that of taking commercial software from a paid-for licence model and moving into the cloud and onto a rental model. In out line, we’ve seen this with CAD packages and notably with EAGLE PCB CAD, but it’s hit other sectors in exactly the same way. The art and design communities, in particular, are feeling the pinch from Adobe Suite going towards a rental model, and now the artist and perennial thorn in the side of anyone who seeks to own a colour, [Stuart Semple] is doing something about it. He’s launching a competing suite called provocatively, Abode, which will follow an affordable paid-for licence model. It’s a development that raises interesting questions for the open source community, so it’s definitely worth a second look from that perspective.
Taking on software rental can only be a good thing, and we hope that the new package gains a foothold for that reason. But since we’re sure that there will be open-source enthusiasts asking the question: why are the established open-source equivalents such as GIMP and Inkscape not the obvious alternatives to the Adobe suite? In there may be some uncomfortable moments of soul searching for the software libre world around usability and interfaces.
Thomas Edison once said that genius was 1% inspiration and 99% perspiration. That doesn’t leave much room for partspiration.
I’m working on a top-secret project, and had to place a parts order on AliExpress with a minimum order quantity of five in order to get decent shipping times. No big deal, financially, and it’s always great to have spares as backup for the ones you fry.
But as I started lighting up the little round smartwatch displays to put them through their paces, I started thinking of all sorts of ways that I could use something like this. I had no idea how easy to drive they were, or frankly, how good they looked in person. When you get a round display in your hands, you find that you need dial indicators everywhere.
And then my son came by and said “Oh neat. I want one!” and started thinking up all sorts of gizmos that I could put them in. Two of them would make awesome eyes, and he’s been on a chameleon kick – the animal, you know. So we’re looking for chameleon eye animations online.
And all of a sudden, I have more projects lined up than I have remaining screens. I’m calling this phenomenon “partspiration”. You know, when you figure out how to use something and then you see uses for it everywhere? Time to place another Ali order.
Gearing Up for the Hackaday Prize
And don’t forget, we just started the next round of the Hackaday Prize: Gearing Up. In this challenge round we want to see your best DIY tools, jigs, and workflow accelerators. Custom reflow plates, home-built power supplies, or even software tools – as long as it helps you get the job done, it has a place here. You’ve got until Aug. 8 to get your entry finished, but head on over to Hackaday.io and get started now.
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There’s a point in a component’s thermal regime that’s between normal operation and overloaded to the point of obvious failure. That’s a dangerous region, because the component isn’t quite hot enough to release the Magic Smoke, but hot enough to singe any finger you poke around with the see if everything’s running right. So if you’re looking to keep your fingerprints unmodified, but you don’t want to invest in a thermal camera, you might want to let this thermochromic breadboard point the way to overloaded components.
We’re not sure where this tip came from, but judging by the look of the website it was sometime in the late 90s. We’re also not sure who’s behind this little hack, so we’ll just credit [improwis]. The idea is pretty simple — white acrylic paint is mixed with thermochromic pigment, and the mixture is carefully painted onto the plastic surface of a standard-issue solderless breadboard. Care is taken to apply thin coats, lest the paint gets into the contacts and really muck things up. Once the paint is dry you’re ready to build your circuit. We have to admit we’re surprised at how sensitive the paint is; judging by the pictures, the heat coming off a 1/4-watt resistor dissipating 350 mW is plenty, even when the body of the resistor is well above the surface of the breadboard. We’d imagine the paint would point out not only hot components but probably the breadboard contacts too, if things got really toasty.
This seems like such a great application of thermochromism, one that’s a bit more useful than clocks and Pi Day celebrations. If you’re going to try this yourself, you’ll have to track down your own supply of thermochromic pigment, though — the link in the article is long dead. That’s not a problem, though, as Amazon sells scads of the stuff, seemingly aimed mainly at nail salons. The more you know.