We remember the floppy disk as the storage medium most of us used two decades or more ago, limited in capacity and susceptible to data loss. It found its way into a few unexpected uses such as Sony’s Mavica line of digital cameras, but outside those who maintain and use older equipment it’s now ancient history.
Seemingly not for [Terence Eden] though, who has made a portable audio player that uses a floppy disk as its storage medium. It came about with the realization that half an hour of extremely compressed audio could be squeezed onto a standard 3.5 inch floppy, and then that the Beatles’ A Hard Day’s Night album comes in at only a shade over that time. With some nifty manipulation of the compression command line and the judicious removal of some unnecessary metadata, the album can fit on a floppy in equivalent quality to the AM radio fans would have heard it over back in 1964.
The player would have been a major undertaking when the floppy was king, but in 2020 it’s simply a USB floppy drive, a Raspberry Pi, and a battery pack. He’s given us the full instructions, and no doubt a more permanent version could be built with a 3D-printed case.
As drone capability and flight time increase, the missions they will fly are getting more and more complex. [Justin] uses a service called ClimaCell which has real-time, forecast, and historical weather data available across the globe. The service isn’t totally free, but if you make fewer than 1,000 calls a day you might be able to use a developer account which doesn’t cost anything.
According to [Justin], weather data can help with pre-flight planning, in-flight operations, and post-flight analysis. The value of accurate forecasting is indisputable. However, a drone or its ground controller could certainly understand real-time weather in a variety of ways and record it for later use, so the other two use cases maybe a little less valuable.
While on the subject, it seems to us that accurate forecasting could be important for other kinds of projects. Will you have enough sun to catch a charge on your robot lawnmower tomorrow? If your beach kiosk is expecting rain, it could deploy an umbrella or close some doors and shutdown for a bit.
If you insist on using a free service, the ClimaCell blog actually lists their top 8 APIs. Naturally, their service is number one, but they do have an assessment of others that seems fair enough. Nearly all of these will have some cost if you use it enough, but many of them are pretty reasonable unless you’re making a huge number of calls.
How would you use accurate micro weather data? Let us know in the comments. Then again, sometimes you want to know the weather right from your couch. Or maybe you’d like your umbrella to tell you how long the storm is going to last.
[Blake]’s interest in building keyboards happened naturally enough — he was looking for a new project to work on and fell into the treasure chest that is the mechanical keyboard community. It sounds like he hasn’t built anything but keyboards since then, and we can absolutely relate.
We particularly like the double rainbow ribbon cable wiring method [Blake] used to connect each row and column to the controller. It looks beautiful, yes, but it’s also a great way to maintain sanity while programming and troubleshooting.
Keyboard builds can look daunting, even at 40% of standard size. But as [Blake] discovered, there are some really good guides out there with fantastic tips for hand-wiring in small spaces. And now there is another well-written guide with clear pictures to point to.
Macro photography is the art of taking photos of things very close up, and ideally at great detail. Unfortunately cameras have poor depth of field at close ranges, so to get around this, many use focus stacking techniques. This involves taking many photos at different focal lengths and digitally compositing them together. To help achieve this, [gtoal] realized that garden variety CNC machines would be perfect for the job.
To focus stack effectively, it’s desirable to move the camera in very small increments of sub-mm precision, in order to get different parts of the subject in focus. For this, a CNC machine excels, as it’s designed to move tool heads in very tiny, precise movements.
To achieve a bargain focus stacking rig, [gtoal] used a Dremel tool mount for cutting discs. It’s repurposed here, used as an easy way to fit a Raspberry Pi camera to a CNC tool head through its mounting holes. From there, it’s a simple manner of stepping the CNC a tiny amount at a time on the Z-axis, while taking photos with the Raspberry Pi along the way. [gtoal] notes that it would be simple for an experienced CNC user to whip up a program to automate the entire process.
We don’t have many details from [dariocose] about his K-Ability Dev Kit yet, but there are enough clues on his HackadayPrize2020 entry that we can tease out the critical points. The plan is to supply a control module with Bluetooth HID capability to act as a mouse and keyboard. It will plug into a socket on user-specific boards. Each style will be suited to a patient with a neuromuscular disease and will allow them to interact with computers in a way that suits their needs. For example, if someone lacks fine motor control, they may need large buttons, while someone with weak muscles may need pads close to one another. From the video’s looks below, the prototype boards aren’t anything fancier than cardboard and wire. Developing the best device doesn’t mean a dozen iterative prints or wasted laser-cut acrylic sheets.
Example code supports three mouse movements, left, right, and down, but there are plans to develop a tool to reprogram them. Given the name and prominent LCD, we suspect there will be keyboard support in the future. Processing and Bluetooth rest on the capable shoulders of an ESP32, which also supports touch sensing, so customized pads can respond to a wispy graze or a blunt fist.
Can it crawl? Can it climb? Can it roll? Can it skate? Can it draw? Naminukas by [Mykolas Juraitis] can do all of those things, and it is the size of a winter boot. Roving robots generally fall into one locomotion category, and the fanciest are amphibious. We categorize this one as transforming between three modes.
The first mode is like an inch-worm and a robot arm. Using a vacuum cup at the hub of each wheel, it sticks one end to the ground then heaves itself in the direction it wants to go and repeats. Its second form is a two-wheel balancing robot, which is the fastest configuration, and it can even carry things on its suckers. For the finale, it can hybridize all the tricks and use a camera dolly like a skateboard. One end sticks to the dolly, and the other is a propulsion wheel.
Naminukas is not just about scooting around the floor, because it can use tools with enough dexterity to write legibly on a whiteboard, climb walls, and even move around the ceiling. If these become sentient, there will be no place to hide, except a room with shag carpet, and is that any way to live?
The Earth’s oceans are a vast frontier that brims with possibilities for the future of medicine, ocean conservation, and food production. They remain largely unexplored because of the physical limits of scuba diving. Humans can only dive for a few hours each day, and every minute spent breathing compressed air at depth must be paid for with a slower ascent to the surface. Otherwise, divers could develop decompression sickness from nitrogen expanding in the bloodstream.
Cousteau’s first sea lab, Conshelf 1 (Continental Shelf Station) held two people and was stationed 33 feet deep off the coast of Marseilles, France. Conshelf 2 sheltered six people and spent a total of six weeks under the Red Sea at two different depths.
Conshelf 3 was Cousteau’s most ambitious habitat design, because it was nearly self-sufficient compared to the first two. It accommodated six divers for three weeks at a time and sat 336 feet deep off the coast of France, near Nice. Conshelf 3 was built in partnership with a French petrochemical company to study the viability of stationing humans for underwater oil drilling (before we had robots for that), and included a mock oil rig on the nearby ocean floor for exercises.
Several underwater habitats have come and gone in the years since the Conshelf series, but each has been built for a specific research project or group of tasks. There’s never really been a permanent habitat established for general research into the biochemistry of the ocean.