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From Fail to Wail: Guitar Picks Made from 3D Printed Waste

5 hours 20 minก่อน

Between failed prints and iterative designs that need a few attempts before you nail them down, a certain amount of wasted material is essentially unavoidable when 3D printing. The good news is that PLA is a bioplastic and can be broken down via industrial composting, but even still, any method that allows you to reuse this material at home is worth taking a look at.

In a recent video, [Noah Zeck] details one potential use for your scrap plastic by turning his failed 3D prints into guitar picks. The idea here could really be applied to anything you can make out of thin plastic sheeting, but the fact that you can easily and cheaply produce picks with a commercially available punch makes this application particularly appealing.

The first step in this process is about as low-tech as it gets: wrap your scrap printed parts in rags, and beat them with a sledge hammer. This breaks them up into smaller and more manageable pieces, which is important for the next step. If the parts are small enough and you’ve got a decently powerful blender you don’t mind devoting to plastic recycling, we imagine that would make short work of this step as well.

Once suitably pulverized, [Noah] puts the plastic on a piece of glass and gets it warmed up with a heat gun. PLA has a fairly low glass transition temperature, so it shouldn’t take much time to soften. Then he puts a second piece of glass on top and squeezes them together to get a thin, flat sheet of plastic. Once cooled, he punches his guitar picks out of the sheet, with bonus points if the colors swirled around into interesting patterns. If you’re not musically inclined, we’ve seen a very similar method used to produce colorful floor tiles.

Controlling Tremors As They Happen

อาทิตย์, 12/08/2019 - 22:01

Some neurological disorders, like Parkinson’s disease, can cause muscle tremors which can get worse as time goes along. In the beginning it may not be too difficult to manage, but as the disease progresses the tremors get worse and worse, until day-to-day movements are extremely difficult. Even picking up a fork or pouring a glass of water becomes nearly impossible. Some helpful tools have been designed to limit the impacts of the tremors, but this new device seeks to dampen the tremors directly.

A research team from Fresno State has been developing the Tremelo, which is a hand stabilizer that straps onto the arm of a person suffering from tremors. It has sets of tuned mass dampers in each of two enclosures, which rapidly shift the weights inside to counter the motion of the wearer’s tremors. The device has already shown success in 36 trial patients and does an incredible job at limiting the amount of tremors the user experiences, and also has a bonus of being non-invasive for the wearer.

The team has successfully trialed the program, but is currently seeking funding on Indiegogo. The project seems worthwhile and is a novel approach to a common problem. In the past, devices (admittedly with a much cheaper price tag) try to solve the problem externally rather than in the direction that the Tremelo has gone, and it’s a unique idea that shows a lot of promise.

Death to all Coca Cola Cans with This Miniature Arduino Powered Cannon

อาทิตย์, 12/08/2019 - 19:01

[MJKZZ] sends in this entertaining little tutorial on building a small automated cannon out of a syringe.

He starts the build off by modifying an arc lighter, the fancy kind one might use to light a fire on a windy day, so that it can be controlled by a micro-controller. The arc is moved to the needle end of the syringe with a careful application of wires and hot glue. When the syringe is filled with a bit of alcohol and the original plunger is pressed back in a small spark will send it flying back out in a very satisfying fashion.

Of course it wouldn’t be a proper hack without an Arduino added on for no reason other than the joy of doing so. [MKJZZ] adds an ultrasonic sensor into the mix which, when triggered appropriately by an invading object fires the arc lighter using a reed relay.

He demonstrates the build by eliminating an intruding coke can on his work bench. You can see it in the video after the break. All in all a very fun hack.

The Barn Find IBM 360 Comes Home

อาทิตย์, 12/08/2019 - 16:01

It’s a story that may be familiar to many of us, that of bidding on an item in an online auction and discovering once we go to pick it up that we’ve bought a bit more than we’d bargained for. We told you earlier in the year about the trio of Brits who bought an IBM System/360 mainframe computer from the mid 1960s off of a seller in Germany, only to find in the long-abandoned machine room that they’d bought not just one but two 360s, and a System/370 to boot. Their van was nowhere near big enough for all three machines plus a mountain of cabling, documentation, and period storage media, so they moved it to a hastily-rented storage unit and returned home to work out what on earth to do next.

Now we’ve received an email from the trio with some good news; not only have they managed to bring their hoard of vintage big iron computing back home, but also they’ve found a home for it in the rather unusual surroundings of a former top-secret UK Government signals intelligence station. With the help of a friendly specialist IT relocation company they unleashed it from their temporary storage and into the truck for the UK. It’s a tale of careful packing and plenty of wrapped pallets, as we begin to glimpse the true extent of the collection as you can see in the video below the break, because not only have they secured all the hardware but they also have a huge quantity of punched cards and disk packs. The prospect of a software archaeology peek into how a 1960s mainframe was used by its original customer is a particularly interesting one, as it’s likely those media contain an ossified snapshot of its inner workings.

We’re hoping to follow this project as it evolves, and see (we hope) a room full of abandoned junk transformed into a facsimile of a typical 1960s business computing setup. If you’d like to catch up, read our original coverage of the find.

Using Glow-in-the-Dark Fish Gut Bacteria to Make Art

อาทิตย์, 12/08/2019 - 13:01

In New Orleans, a Loyola University professor has been creating original art out of glow-in-the-dark fish gut bacteria, enough to fill 1000 Petri dishes. Her first major foray into art was biomorphic abstractions, inspired by Impressionist painters, with her current work reflecting much of the abstraction of the earlier style.

The bacteria comes from the Pacific Rock Fish and glows a vibrant electric-blue. It is typically kept in a freezer and has a texture and color similar to water when it’s being used. The luminescence only lasts for 24 hours, presenting timing challenges when preparing artwork for a photoshoot, as artist [Hunter Cole] often does. With a Q-tip, [Cole] paints roses, lilies, and insects onto the Petri dishes and arranges them for surreal photography shoots. In addition to painting shapes in agar, she uses a light painting technique by filling clear water bottles with the bacteria for long-exposure shots.

[Cole] is planning on presenting her work at an art exhibit in New Orleans, along with showcasing a performance piece featuring models clad in chandelier-like costumes glowing with bioluminescent bacteria in petri dishes.

File Systems for Tiny Devices

อาทิตย์, 12/08/2019 - 10:01

Sometimes you build a computer and use it every day. Sometimes you build a different type of computer and it sits alone on a mountaintop for years. The design considerations for these two setups are remarkably different, right down to the type of file system used. For small computers like [Jo] is using, and for the amount of time they sit alone in remote locations, he decided to build his own file system for them.

Known as JesFs ([Jo]’s embedded serial File system), the file system is for SPI Flash and intended for use in scientific data logging. It can be used on the chip-scale processors found in many development boards, and is robust enough to use in applications where remoteness is a concern. It has a small RAM footprint, is completely open source, includes wear leveling, and has a number of security features built-in as well.

Some of the benefits of using a file system on such a tiny chip aren’t immediately obvious unless you’re doing a lot of data logging, but it does allow you to change virtually any aspect of the firmware much more easily if everything is accessible as a file, and not something you would have to change by reflashing the whole chip, for example. There are also a number of traps that you can easily fall into when working with file systems for tiny devices.

ESP32 Audio Sampling with Interrupts and IRAM

อาทิตย์, 12/08/2019 - 07:01

Interrupting while someone is talking is rude for humans, but smart for computers. [Ivan Voras] shows how to use interrupts to service the ESP32 analog to digital converters when sampling sound. Interestingly, he uses the Arduino IDE mixed with native ESP-IDF APIs to get the best performance.

Like most complex interrupt-driven software, [Ivan’s] code uses a two-stage interrupt strategy. When a timer expires, an interrupt occurs. The handler needs to complete quickly so it does nothing but set a flag. Another routine blocks on the flag and then does the actual work required.

Because the interrupt service routine needs to be fast, it has to be in RAM. [Ivan] uses the IRAM_ATTR attribute to make this work and explains what’s going on when you use it.

…the CPU cores can only execute instructions (and access data) from the embedded RAM, not from the flash storage where the program code and data are normally stored. To get around this, a part of the total 520 KiB of RAM is dedicated as IRAM, a 128 KiB cache used to transparently load code from flash storage.The ESP32 uses separate buses for code and data (“Harvard architecture”) so they are very much handled separately, and that extends to memory properties: IRAM is special, and can only be accessed at 32-bit address boundaries.

This is very important because some ESP-IDF calls — including adc1_get_raw — do not use this attribute and will, therefore, crash if they get pushed out to flash memory. At the end, he muses between the benefit of using an OS with the ESP32 or going bare metal.

If you want to know more about the Arduino on ESP32, we covered that. We also dug deeper into the chip a few times.

Learn Water Purification Techniques with this STEM Learning Kit

อาทิตย์, 12/08/2019 - 04:01

We see a lot of great STEM education projects. These projects have a way of turning into something much larger. How many commercial devices and machines are built on Raspberry Pi’s and Arduinos? [Ryan Beltrán] is using common materials to teach people how to clean water. This particular kit demonstrates a water purification process called electro-coagulation.

When current is passed through two electrodes suspended in water it changes the surface charge on the suspended solids. This causes the solids, metals, and oils to clump together which makes them considerably easier to treat and clean.

The kit consists of a jar, electrodes, some 3D printed parts, and a pre-flashed Arduino. There’s also salts and filters to finalize the purification process. Students can start the experiment right away and if they’re inspired they’ll have all the tools to try more advanced techniques.

Often STEM kits lean heavily to robotics or computer science, but there are so many vast and interesting fields out there with problems that need to be solved.

The HackadayPrize2019 is Sponsored by:





Beer Keg Becomes High-Performance Pizza Oven

อาทิตย์, 12/08/2019 - 01:00

Pizza varies all around the world, with several cities having put their own mark on the Italian dish. To make an authentic pie in the Neapolitan style requires extremely high temperatures in order to cook the pizza through in just a couple of minutes. Armed with a beer keg and some ingenuity, [AndrewW1977] got down to work, building a rig that could get the job done.

The build starts by cutting the keg in half. A series of zigzag steel pieces are welded inside, in order to give the refractory cement more surface area to stick to. With the cement poured and set, a handle was welded to the keg for ease of use, as well as a thermometer to monitor internal temperatures.

Initial attempts to cook using the rig used a wood-fired rocket stove design. This had the drawback of taking up to 45 minutes to reach the appropriate temperature, so the build then switched to using God’s Gas, clean burning propane, as a fuel source. With a jet-style burner installed in the base, the oven was ready to start turning out pizzas.

The idea of cooking a hot, fresh pizza in just a couple of minutes has us salivating at the possibilities. We’ve seen other high-speed pizza ovens, too. Video after the break.

Upgrade Your Shades to Find Lost Items

เสาร์, 12/07/2019 - 22:00

Ever wish you could augment your sense of sight?

[Nick Bild]’s latest hack helps you find objects (or people) by locating their position and tracking them with a laser. The device, dubbed Artemis, latches onto your eyeglasses and can be configured to locate a specific object.

Images collected from the device are streamed to an NVIDIA Jetson AGX Xavier board, which uses a SSD300 (Single Shot MultiBox Detection) model to locate objects. The model was pre-trained with the COCO dataset to recognize and localize 80 different object types given input from images thresholded in OpenCV. Once the desired object is identified and located, a laser diode activates.

Probably due to the current thresholds, the demo runs mostly work on objects placed further apart against a neutral background. It’s an interesting look at applications combining computer vision with physical devices to augment experiences, rather than simply processing and analyzing data.

The device uses two servos for controlling the laser: one for X-axis control and the other for Y-axis control. The controls are executed from an Adafruit Itsy Bitsy M4 Express microcontroller.

Perhaps with a bit more training, we might not have so much trouble with “Where’s Waldo” puzzles anymore.

Check out some of our other sunglasses hacks, from home automation to using LCDs to lessening the glare from headlights.

Simple Pogo Programmer for ESP8266 Modules

เสาร์, 12/07/2019 - 19:00

ESP8266 development boards like the Wemos D1 Mini and NodeMCU are an excellent way to get a one-off project up and rolling quickly, but their size and relative complexity mean they aren’t necessarily a good choice for even short-run production hardware. On the other hand, programming the bare ESP modules can be something of a pain. But thanks to [Greg Frost], flashing those tiny little boards just got a lot easier.

His 3D printed design uses pogo pins to securely connect to the board’s castellated edges, which also holds it in place during the programming process. On the back side there’s just a few jumper wires and a couple of resistors, which ultimately lead to the FT232R FTDI board that actually connects the chip to the computer so you can program it.

We’d like to see a back panel that encloses the wiring, and perhaps an alternate version that deletes the space for the FTDI board in favor of a row of header pins. Both easy enough modifications to the basic design should [Greg] or anyone else feel so inclined. But even as it is, this is a great little programmer that can be sourced and assembled easily and cheaply.

This isn’t the first 3D printed ESP8266 programmer we’ve seen, and there are some improvised versions which are even cheaper to put together, but this design has a certain professional look that we think will be right at home on your bench.

This CPU Has Only One Instruction

เสาร์, 12/07/2019 - 16:00

Most of us will be familiar at some level with the operation of a basic CPU, usually through exposure to microprocessors of the type that find their way into our projects. We can look at its internal block diagram and get how it works, see the registers and ALU, follow the principles of a von Neumann architecture, and understand that it has an instruction set with different instructions for each of its functions. We all know that this only describes one type of CPU though, and thus it’s always interesting to see alternatives. [Ike Jr] then has a project that should provide a lot of interest, it’s a CPU that only has a single instruction. It can only move data from one place to another, which seems to preclude any possibility of computation. How on earth can it work?

The machine has a set of registers as well as memory, and it achieves computation by having specific registers where we might expect to see instructions. For example the AND register is a two-position stack, that when it is full computes the AND of its two pieces of data and places the result in a general purpose register. The write-up goes into significant detail on the CPU’s operation, and while it’s unlikely the world will move en masse to this architecture it’s still a very interesting read. For now this is a machine that exists in software simulation rather than in silicon, and he’s working to release it so enthusiasts for unusual CPUs can have a go.

The idea of having registers that compute reminds us of a transport triggered architecture machine, being not the same as a one instruction CPU with a more conventional computing instruction.

Abstract PCB header image: Harland Quarrington/MOD [OGL v1.0].

Visiting the FACOM 128B 1958 Relay Computer

เสาร์, 12/07/2019 - 13:00

If you study the history of computing you might have heard of the FACOM 128B, a Japanese relay computer from 1958. It holds the distinction of being a contender for the oldest computer that still works in its original form, as it resides in a Fujitsu building in Numazu Japan. [CuriousMarc] visited the old computer and created a video about it as well as painting a picture of other contemporary machines. You can see the video below.

[Marc] explains how a relay machine was already behind the times in 1958, and also shows how the 5,000 relay machine is laid out. The machine on display came from a Tokyo university and did the kind of computations you might use a computer for today to do engineering design.

Watching — and hearing — the beast run a program to add three and three is very illustrative. The keyboards reminded us of old adding machines. The machine uses floating point or bi-quinary that stores each digit as 7 bits. This led to a wide word width but made it simple to see when a relay got stuck since each number had two parts and only one relay was on in each part for any number.

The video isn’t just a home movie of the visit but shows how the operator entered data and instructions along with how to read the output display. The machine had 180 words of memory that took several cabinets. That works out to about 13K of memory. That was still enough to set up the solution for a 5×5 matrix inversion. We were amused to see that a program loop was literally a loop of punched tape.

We like flying a jet plane but are nostalgic for airships. By the same token, we kind of wish our desktop computer used relays like this. We’d probably be pretty unhappy if either of those were really true. Then again, we have seen a single board relay computer recently.

We’ve actually seen this computer in an earlier post. There we noted the computer was asynchronous, something that would be unusual in a modern CPU.

Behind Amazon’s Doors is a Library

เสาร์, 12/07/2019 - 10:00

Some people love Amazon, while others think it has become too big and invasive. But you have to admit, they build gigantic and apparently reliable systems. Interestingly, they recently released a library of white papers from their senior staff called the Builder’s Library.

According to their blog post:

The Amazon Builders’ Library is a collection of living articles that take readers under the hood of how Amazon architects, releases, and operates the software underpinning Amazon.com and AWS. The Builders’ Library articles are written by Amazon’s senior technical leaders and engineers, covering topics across architecture, software delivery, and operations. For example, readers can see how Amazon automates software delivery to achieve over 150 million deployments a year or how Amazon’s engineers implement principles such as shuffle sharding to build resilient systems that are highly available and fault tolerant.

The Amazon Builders’ Library will continue to be updated with new content going forward.

Right now there are only two topic areas: Architecture and Software Delivery/Operations. There are however a number of papers in each topic. For example, “Challenges with Distributed Systems” gives an overview of best practices for building systems with multiple computers.

Other papers cover things such as leader election, load shedding, and effective caching. Overall, it looks like a lot of interesting reading.

Amazon is into a dizzying array of services these days, ranging from satellite ground stations to oddball ways to deliver your latest coffee mug.

Inkjet Printing On The Cheap With A Continuous Ink System

เสาร์, 12/07/2019 - 07:00

Inkjet printers are cheap to buy, but expensive to run. Replacement cartridges can easily cost double the price of the hardware itself, leading many to decry the technology entirely. However, the hackers of the world have the problem licked – enter the continuous ink system.

[cprossu] wanted an affordable color printing solution for the hackerspace. A cheap printer was sourced from a thrift store. The model chosen was selected for its lack of cartridge DRM and the availability of kits on eBay for conversion to a continuous ink system. This involves running large refillable tanks of ink instead of small individual cartridges which must be thrown away when empty.

[cprossu] discusses both the challenges you’ll likely face in a general build, as well as the specific work required to handle the conversion on an Epson Artisan 725. There’s also excessive label-maker abuse, which always brings a smile to our face. It’s a conversion well worth considering if you find yourself regularly purchasing expensive cartridges. We’ve even seen similar builds as far back as 2009, right from the ground up!

Swapping the ROMs in Mini Arcade Cabinets

เสาร์, 12/07/2019 - 04:00

You’ve probably seen a few of these miniature arcade games online or in big box retailers: for $20 USD or so you get scaled-down version of a classic arcade cabinet, perfect for a desk toy or to throw up on a shelf as part of your gaming collection. Like any good Hackaday reader, you were probably curious about what makes them tick. Thanks to [wrongbaud], we don’t have to wonder anymore.

Over the course of several blog posts, [wrongbaud] walks readers through the hardware and software used in a few of these miniature games. For example, the Rampage cabinet is using a so-called “NES on a Chip” along with a SPI flash chip to hold the ROM, while Mortal Kombat is using a Genesis emulation solution and parallel flash. It wouldn’t be interesting if they didn’t throw you a few curves now and again, right?

But these are more than simple teardowns. Once [wrongbaud] gives an overview of the hardware, the next step is reading the respective flash storage and trying to make sense of the dumped data. These sort of games generally reuse the hardware among a number of titles, so by isolating where the game ROM is and replacing it, they can be made to play other games without hardware modification. Here, this capability is demonstrated by replacing the ROM data for Rampage with Yoshi’s Cookie. Naturally it’s one of those things that’s easier said than done, but it’s an interesting proof of concept.

The Mortal Kombat cabinet is a newer addition to the collection, so [wrongbaud] hasn’t progressed quite as far with that one. The parallel flash chip has been dumped with the help of an ESP32 and a MCP23017 I/O expander, and some Genesis ROM headers are identifiable in the data, but there’s still some sifting to be done before the firmware structure can be fully understood.

Even if you’re not in the market for a diminutive arcade experience, the information that [wrongbaud] has collected here is really phenomenal. From understanding protocols such as I2C and SPI to navigating firmware dumps with a hex editor, these posts are an invaluable resource for anyone looking to get started with reverse engineering.

David Williams Is “FPGA-Curious”

เสาร์, 12/07/2019 - 02:30

If you hadn’t noticed, we had a bit of an FPGA theme running at this year’s Superconference. Why? Because the open-source FPGA toolchain is ripening, and because many of the problems that hackers (and academics) are tackling these days have become complex enough to warrant using them. A case in point: David Williams is a university professor who just wanted to build a quadruped robotics project. Each leg has a complex set of motors, motor drivers, sensors, and other feedback mechanisms. Centralizing all of this data put real strains on the robot’s network, and with so many devices the microcontrollers were running out of GPIOs. This lead him to become, in his words, “FPGA-curious”.

If you’re looking for a gentle introduction to the state of the art in open-source FPGAs, this is your talk. David covers everything, from a bird’s eye view of hardware description languages, through the entire Yosys-based open-source toolchain, and even through to embedding soft-CPUs into the FPGA fabric. And that’s just the first 18 minutes. (Slides for your enjoyment, and you can watch the talk embedded below the break.)

The second half of the talk is more about his personal experience and advice based on the last year or so of his experience going from FPGA newbie to master of his own robot. He highlights the versatility of a soft-CPU in an FPGA versus a pre-baked microcontroller solution. With the microcontroller you get all of the peripherals built into the silicon, but with the FPGA you get to write your own peripherals. Want a 10-wire SPI-like bus? Just code it up. Your peripherals are as simple or complex as you need them to be.

On the hardware side, David touts the PMOD standard (a man after our own heart!) and points out the large ecology of PMOD-compatible devices out there. Going for a plug-in solution also means that your engineering job is reduced to building a carrier board that can seat the FPGA brainboard of your choosing and interface it with a bunch of PMODs. It’s hard to get much simpler than that.

David is very much interested in the software layer as well, and encouraging re-usability of Verilog code among designs. Towards this end he’s written his own bus and interconnect standard, and a few modules that do things such as buffer data, process video, and so on. While we would have probably gone for the open-source standard WISHBONE interconnect architecture, David bundled a bunch of the possible signals together and called it a “pipe”. Compared to WISHBONE, David’s design makes a few judicious choices and thus streamlines interconnection greatly. He has code to go with it all, so have a look if you’re interested. We’re just speculating, but if you wrote a “pipe” to WISHBONE connector, you’d have the best of both worlds.

Finally, David isn’t just whistling Dixie. He took a video camera, plugged it into his Supercon badge via the cartridge slot, and had it displaying video in real time, all of this using pieces of code that he’d previously written and simply connected together with his “pipes”. A great demo is very convincing.

In sum, David’s talk is a great summary of the state of play in open-source FPGAs right now. Whether you’re getting your first taste, or are a moderately skilled FPGA developer, there is something for you here. And if anything, David’s call to end the fifty years of secrecy and IP-hoarding that have surrounded FPGAs is a rallying cry that we can get behind. We’ve gotten the tools in our hands now, and the hardware has become cheap and accessible. If you’re looking for a place to start, try the self-guided FPGA workshop from Supercon, and then maybe Al Williams’ FPGA Bootcamp. The time for a hacker FPGA revolution is ripe. To arms!

Chandrayaan-2 Found by Citizen Scientist; Reminds Us of Pluto Discovery

เสาร์, 12/07/2019 - 01:01

What does Pluto — not the dog, but the non-Planet — have in common with the Vikram lunar lander launched by India? Both were found by making very tiny comparisons to photographs. You’d think landing something on the moon would be old hat by now, but it turns out only three countries have managed to do it. The Chandrayaan-2 mission would have made India the fourth country. But two miles above the surface, the craft left its planned trajectory and went radio silent.

India claimed it knew where the lander crashed but never revealed any pictures or actual coordinates. NASA’s Lunar Reconnaissance Orbiter took pictures several times of the landing area but didn’t see the expected scar like the one left by the doomed Israeli lander when it crashed in April. A lot of people started looking at the NASA pictures and one Indian computer programmer and mechanical engineer, Shanmuga Subramanian, seems to have been successful.

According to Shanmuga and NASA, he looked at the last known position and velocity and used it to estimate where there might be debris. A white speck about a kilometer away from the proposed landing site wasn’t there on earlier images of the same area. NASA received the report of the suspected finding and confirmed it along with finding a spray of debris.

Is It or Isn’t It?

According to NASA, the camera resolution is about 1.3 meters per pixel and the largest debris is about two square pixels. The Indian Space Research Organization (ISRO) claims they already knew where the lander crashed. On the other hand, a senior ISRO official has cast doubt on the NASA images, although he points out he is stating his personal views. Still, you’d presume if they know where it is, they would know for sure if the NASA analysis is correct or not.

See For Yourself

NASA has a great before and after image that shows the difference very clearly. You can see it below:

Pluto in a Blink

This couldn’t help but remind me of how Pluto was discovered using a machine called a blink comparator. This machine dates back to 1904 and — like many things — has been superseded by modern technology. In 1930, scientists knew there was something pulling the orbits of the planets but they didn’t know where it was.

The blink comparator helps you find something that moves by showing you two photographic plates in quick succession. Anything in the same spot on both plates appears stationary. Anything moving in the frame will stand out as it appears to jump from one spot to another.

In 1906, Percival Lowell started searching for “Planet X” in earnest. He died ten years later never knowing that he had photographed Pluto twice in 1915 but failed to notice it. Retrospectively, there were at least 14 other photographs of the quasi-planet that no one noticed at the time, going back to 1909.

In 1929 — after a lot of legal battles between the Lowell Observatory and Lowell’s widow, the search resumed with Clyde Tombaugh given the task as something suitable for a young astronomer. Tombaugh took pictures of the night sky in pairs and used a blink comparator to see if anything moved. He had a 13″ telescope — respectable, but not huge by today’s standards.

 

The discovery came out in March of 1930. Did you know that since then Pluto still hasn’t made it all the way around the sun? A year on Pluto is nearly 250 Earth years long. You can see more about the comparator at the Lowell Observatory in the video below.

Modern Science

While Tombaugh wasn’t technically a citizen scientist, we have access to tools he couldn’t dream of. While blink comparators are a thing of the past, we have a whole arsenal of digital imaging tools along with large numbers of images from ground-, space-, and vehicle-based telescopes and cameras. We applaud Shanmuga Subramanian for making use of these tools so successfully.

You can even do observations with a crowd if you like. You can also use some pretty big scopes online. Meanwhile, good luck to ISRO with their third mission, coming soon.

Hackaday Podcast 045: Raspberry Pi Bug, Rapidly Aging Vodka, Raining on the Cloud, and This Wasn’t a Supercon Episode

เสาร์, 12/07/2019 - 00:01

Hackaday editors Mike Szczys and Elliot Williams talk over the last three weeks full of hacks. Our first “back to normal” podcast after Supercon turns out to still have a lot of Supercon references in it. We discuss Raspberry Pi 4’s HDMI interfering with its WiFi, learn the differences between CoreXY/Delta/Cartesian printers, sip on Whiskey aged in an ultrasonic jewelry cleaner, and set up cloud printing that’s already scheduled for the chopping block. Along the way, you’ll hear hints of what happened at Supercon, from the definitive guide to designing LEDs for iron-clad performance to the projects people hauled along with them.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!



Direct download (71 MB)

Places to follow Hackaday podcasts:

Episode 045 Show Notes: New This Week: Interesting Hacks of the Week: Quick Hacks: Can’t-Miss Articles:

Tuning Up the ThinkGeek Star Trek Intercom Panel

ศุกร์, 12/06/2019 - 23:30

On Star Trek, all Kirk and friends had to do was snap the button on the always conveniently located intercom panel, start talking, and the intended recipient would immediately respond no matter where they were in the ship. How did it work? Who knows. In spite of, or perhaps even because of, the lightly-explained nature of the technology, the cherry-red wall intercoms still hold a certain charm for fans of the groundbreaking show.

A viewer sent [Fran Blanche] a scaled down replica of the intercom from ThinkGeek, and while it certainly looks fairly close to the original prop, it has a couple of annoying design elements. When triggered by the side-mounted motion sensors, the panel will play either the iconic swoosh of the automatic doors or the “Red Alert” sound effect. It’s a cute idea for a kid’s bedroom maybe, but not exactly ideal for somebody who regularly records YouTube videos.

Peak 23rd century technology

So the first order of business was to cut the motion sensors out of the circuit and replace them with a push button. [Fran] draws up a quick diagram to explain how these sensors work, and shows that they can easily be bypassed with a momentary switch since they normally bring the line high when triggered. She then converted the indicator light on the right side of the panel into a button to enable the alert sound effect, which is more accurate to how it worked in the show anyway.

The other issue, and perhaps the most egregious to Star Trek fans, is that the “Red Alert” indicator on the top of the panel didn’t actually flash like it did in the show. To design and build this panel and not put a few LEDs behind that piece of frosted plastic seems a bit like producing a Matchbox car and forgetting to make the wheels spin. With a couple of red LEDs and a bit of new wiring, the oversight was quickly rectified.

While it might not be perfect, at least ThinkGeek actually produced a functional product this time. It could have ended up like one of their April Fool’s “products” that never get put into production, forcing a desperate Trekkie to begrudgingly build his own version.