Re-Creating the Apollo DSKY’s Display

Apollo astronauts used the DSKY (Display-Keyboard) to interact with the flight computer with a series of 2-digit codes punched into a numeric keypad. Above the keyboard was a high voltage electroluminescent (EL) display whose segments were driven by electromechanical relays; old-ass technology not seen in operation in decades.

[Fran Blanche] is working to re-create the DSKY’s display, and is raising funds to make her first prototype. She was actually able to go dismantle a real DSKY at the Smithsonian, and this drove her desire to re-create the DSKY’s unusual display.

As [Fran] points out in her video, cinematic re-creations typically involve LED displays and CGI rather than the authentic EL 7-segs. Who would want that when you could have the original?

The DSKY is one of the most recognizable and historically relevant parts of the Apollo Command Module and it’s also quite rare. There are only a handful of  them around and of course none of them work. [Fran]’s display could help museums, collectors — and yes, moviemakers — re-create DSKYs with greater authenticity.

[Fran] is a good friend of Hackaday. If you missed her Hack Chat on antiquated technology last Friday you can check out the transcript here.

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Float Spectrum, a Sound-Reactive Installation

[Sam Kent] and friends built a sound-reactive LED display as part of the Leeds (UK) Digital Festival and exhibited it at Hyde Park Book Club. The installation consists of a grid of 25 tubes, each one made out of four recycled 2-liter bottles equipped with a string of a dozen WS2812B LEDs controlled by a central Arduino.

Connected to the Arduino via USB, a computer running a Processing application analyzes the audio input and tells the Arduino which LEDs to light and when. The red tube in the center responds to bass, the ring of yellow LEDs mids, and the outer ring glows blue in response to high frequencies.

It’s amazing how just a simple 2-liter makes a rather effective light pipe to amplify the effect of each burst of color. We think this installation would be a great addition to the magnificent LED dance floor we recently looked at from our friends up in Toronto. If you seek an LED art piece that’s a lot easier to move around, what you’re after is a rave shopping cart.

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Crossing The Atlantic In A 42 Inch Boat

In the world of sailing, there are many records to compete over. Speed records, endurance records, size records. The fastest crossing, the longest solo journey, the largest yacht.

But not all records concern superlatives, for example in the size stakes, there are also records for the smallest vessels. The Atlantic crossing has been completed by a succession of ever smaller boats over the years, and the current record from 1993 is held by the 5’4″ (1.626m) boat Father’s Day.

Records are made to be broken, and there is now a challenger to the crown in the form of the impossibly tiny 42″ (1.067m) Undaunted, the creation of [Matt Kent], who intends to sail the boat from the Canary Islands to the USA in around 4 months.

The boat’s design is definitely unusual, with a square aluminium hull of equal beam and length, and a very deep keel that has an emergency drinking water tank as its ballast. The sail is a square rig — imagine picture-book images of Viking ships for a minute — and it has two rudders. We are not nautical engineers here at Hackaday, but reading the descriptions of the boat we understand it to have more in common with a buoy in the way it handles than it does with a sleek racing yacht.

Unfortunately the first sailing attempt suffered a setback due to a design flaw in the way the vessel’s emergency flotation is attached. This was revealed by its interaction with some unusual waves. But [Matt] will be back for another try, and with luck we’ll see him on our TV screens sometime next year as he emerges into the Florida sunshine from his cramped quarters. Meanwhile his unusual boat and its construction makes for a fascinating read that we’re sure you’ll appreciate.

We don’t often cover boat building here at Hackaday. But if unusual ocean crossings are of interest, here’s an autonomous one we looked at back in 2010.

[via Yachting World]

Hackaday Prize Entry : DEER — An Electronic Repellent

Ultrasonic repellent devices used to keep away insects, rodents, birds, and even large animals have been around for quite a while, but their effectiveness depends on who you ask.  Some critters just don’t seem affected, while some others definitely will avoid being around such a device. Deploying a few of these devices to scare off animals seems to be working quite well for [Ondřej Petrlík]. Around where he lives, the fields of tall grass need to be mowed down during the spring. Unfortunately, the tall grass is ideal for young, newborn animals to stay hidden and safe. The mowing machines would often cripple and hurt such animals, and [Ondřej] desperately wanted to solve the problem and prevent these mishaps.

He built an electronic repeller to keep away wild animals and their young from his farm/ranch/range back in the Czech Republic. He used an Arduino Mini to drive a large piezo transducer to scare away the wild animals from the vicinity of the device. He likely used a high enough frequency beyond human range, but we’ll know more when he publishes his code and details. There are also a few large 10mm LED’s – either to visually locate the device or help drive the animals away in conjunction with the ultrasound, with an LDR that activates the LEDs at night. Using the Arduino helps to turn on the transducer at random intervals, and hopefully, he is using a range of different frequencies so the animals don’t become immune to the device.

His first prototype was cobbled together using vanilla, off the shelf parts. An Arduino, a step up converter, an LDR, a couple of LEDs, a reed switch for powering it on via a magnet, and a large ultrasonic transducer, all powered by three alkaline AA batteries. He stuffed it all inside a weatherproof molded enclosure, holding it all together with a lot of hot glue. This didn’t make it very rugged for the long-term, outdoor field use. While the prototype worked well, he needed several of the devices to be placed all around his farm. To make assembly easy and make it more reliable, he designed a custom PCB to fit in the weather proof enclosure. This allowed him to easily mount all the required parts for a more reliable result. His project is still a work in progress, so if you have worked with these types of ultrasonic repellent devices to keep away animals, and have any insights that may help him, do chime in with your comments. [Ondřej] seems pretty satisfied with the results so far.

Metal 3D Printing: Insta-Layers

Selective Metal Sintering is cool but slow. Fear not, a technology that was initially developed to smooth and pattern laser beams is here to save the day, according to a new paper by Lawrence Livermore researchers.

In a paper titled “Diode-based additive manufacturing of metals using an optically-addressable light valve,” the researchers lay out a procedure for using an array of high-powered laser diodes among other things to print a whole layer of metal from powdered metal at one time. No more forward and backward, left and right. Just one bright flash and you’re done. Naturally, the technology is still in its infancy, but huge 3D printed metallic parts are something we’ve always hoped for.

According to [Matthews], the first author of the paper, the mojo of the process comes from a customized laser modulator: the Optically Addressable Light Valve which functions similarly to liquid crystal-based projectors but can handle the high energies associated with powerful lasers. There’s more information straight from the paper’s authors in this phys.org interview.

While it’s true that now is the time for direct metal 3D printing, it appears that for the time being the average hacker is stuck with alternative methods for printing metal. While it’s not the same, pewter casting with PLA might suffice.

Thanks to [Kevin] for sending this in!

Digital Clock Goes with the Grain

This good-looking clock appears to be made out of a block of wood with LED digits floating underneath. In reality, it is a block of PLA plastic covered with wood veneer (well, [androkavo] calls it veneer, but we think it might just be a contact paper or vinyl with a wood pattern). It makes for a striking effect, and we can think of other projects that might make use of the technique, especially since the wood surface looks much more finished than the usual 3D-printed part.

You can see a video of the clock in operation below. The clock circuit itself is nothing exceptional. Just a MAX7218 LED driver and a display along with an STM32 ARM processor. The clock has a DHT22 temperature and humidity sensor, as well as a speaker for an alarm.

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Retrotechtacular: The Transistor (1953 Film)

If we cast our minds back to the early years of the transistor, the year that is always quoted is 1947, during which a Bell Labs team developed the first practical germanium point-contact transistor. They would go on to be granted the Nobel Prize for their work in 1956, but the universal adoption of their invention was not an instantaneous process. Instead there would be a gradual change from vacuum to solid state that would span the 1950s and the 1960s, and even in the 1970s you might still have found mainstream devices on sale containing vacuum tubes.

First point contact transistor via kasap3

To speed up this process, Bell Labs made every effort to publicize their invention. Thus we come to our subject today, their 1953 publicity film The Transistor, in which the electronics industry of the era is described and how each part of it might revolutionize by the transistor is laid out.

We start with a look at a selection of electronic components, among which are a few transistors. The point contact device is already described as superceded by the junction transistor, but as well as those two we are shown a phototransistor and a junction tetrode, a now-obsolete design that had two base connections.

Unexpectedly we don’t dive straight into the world of transistors, but take a look back at the earlier years of the century to the development of vacuum electronics. We’re taken through the early development  and operation of vacuum tubes, then their use in long-distance radio communications, through the advent of electronics in mass entertainment, and finally into the world of radar and microwave links. Only then do we return to the transistor, with a posed shot of [John Bardeen], [William Shockley], and [Walter Brattain] hard at work in a lab. The merits of the transistor as opposed to the tube are then set out, though we can’t help wondering whether they have confused a milliwatt and a microwatt when they describe the transistor as requiring only a millionth of a watt to operate.

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