We don’t all need super high quality electronic testing gear. Sometimes second-hand or inexpensive equipment is accurate enough to get the job done. Though it can be a bit annoying to miss out on some of those “luxury” features. [Ekriirke] had this problem with his cheap multimeter. He wished the LCD screen had a backlight for easier visibility, so rather than upgrade to a more expensive unit he just added one himself.
After opening up the multimeter [Ekriirke] found that it ran on a single 12V battery. He realized that the simplest thing to do would be to wire up four white LEDs in series. The four LEDs were arranged within the case off to each side of the LCD, one in each corner. The leads were bent at 90 degree angles and soldered together “dead bug” style. Thin strips of copper foil tape were attached to the PCB in such a way that the anode and cathode from the LEDs would make contact when the case was closed back up.
The tape wraps around to the other side of the PCB where there was more room for the next piece of the circuit. A capacitor, resistor, and transistor are used in conjunction with a momentary switch. This circuit allows [Ekriirke] to turn on the light for about ten seconds by pressing the button one time. The circuit also runs through the meter’s dial switch, preventing the LEDs from being turned on while the meter itself is turned off.
Filed under: led hacks
Week 18 has faded into history, but not before you wrote some great captions! A hearty thanks to all the entrants. Astute reader [jlbrian7] has done it again! He’s uncovered the story behind this image. The woman in this photo is manually analyzing photographs of charged particles taken in a bubble chamber. He linked to an article from Fermilab, and to a 1971 film about Gargamelle, CERN’s largest bubble chamber at the time. The film is well worth a watch. It’s aimed at the layman, explaining the design, construction, and operation of bubble chambers. The photo scanning section starts at 14:40. The video has plenty of “1970’s-isms”, such as referring to the women analyzing the photographs as “scanning girls”. The filmmaker even bookend the section with an actual scanned girl – a possibly NSFW (by today’s standards) ASCII art printout of a nude pin-up model, as printed by a Control Data Corporation supercomputer.
- “Tabatha, the dungeon master, plots tonight’s dungeon and dragons game inside the exploded atom.”- [LloydTCannonIII]
- “CERN, the only place you can watch Netflix on the same table that you eat lunch and plot global domination. Muwahahaha!” – [Joshua]
- “They take Kerbal Space Program very serious at CERN. Here you can see the first interactive real time orbital view display.” – [haxtormoogle]
This week’s winner is [Jarrett] with “Friday night is Missile Command night in the lab. It’s a serious event”
We’re giving away two prizes this week – one to [jlbrian7] for his research on this and other CERN images, and one to [Jarrett] for his winning caption! Congrats to both of you. Enjoy your Logic Pirates From The Hackaday Store!Week 19
Just about every workplace has to worry about safety. Many companies have a safety team that is trained to handle emergencies and help patients until proper medical technicians arrive. In a typical office environment this training is pretty easy, but what if you’re working on the bleeding edge of science? CERN’s safety team trains for everything, including badly burned hands and partially removed eyeballs. Don’t worry, these are just simulated injuries, which is probably why this CERN scientist is so calm, even smiling for the photo! CERN’s medical room also appears to be well stocked – with a full skeleton, and no less than four different types of fire extinguishers.
So, even though we already have a pretty good idea of what is going on in this photo (and the accompanying album), we’re sure you’ll come up with some great captions. Have at it!
This week’s prize is a Lightblue Bean from The Hackaday Store. Add your humorous caption as a comment to this project log. Make sure you’re commenting on the contest log, not on the contest itself (or on this post).
As always, if you actually have information about the image or the people in it, let CERN know on the original image discussion page.
Filed under: contests, Hackaday Columns
The C.H.I.P. from Next Thing Co. bills itself as the world’s first nine dollar computer. That’s not a lie; their Kickstarter took in over two million dollars for a tiny single board computer with composite Video, WiFi, Bluetooth 512MB of RAM, 4GB of storage, and a 1GHz CPU. That’s a complete computer, sans keyboard, mouse, and monitor. You won’t get that with the $35 Raspberry Pi – you’ll need to add a WiFi adapter and an SD card for the same functionality – and you won’t get that with any other single board computer.
Understandably, the C.H.I.P. is already extremely successful. The company behind it has about 50,000 pre-orders, and people lined up to wait until well into next year for this computer. Exactly how Next Thing Co. managed to build a single board computer and send it out the door for nine dollars is a question that has yet to be answered, and is leaving more than a few people puzzled.
The Olimex blog has given their opinion of the C.H.I.P, and if that’s to be believed, the news isn’t good. The guys at Olimex know their stuff when it comes to making cheap single board computers; they have more than a few for sale, and they know what the Flash and DRAM market is like. To them, it’s impossible to sell a computer like the C.H.I.P. at $9. A quote from Allwinner for a similar module is $16 at the quantity Next Thing Co. would be looking at. That’s just the module with RAM and Flash – no Wifi, no board, no connectors. How could it be possible to sell this computer for only $9?C.H.I.P., a small single board computer available for $9.
Anyone who has ever seen a Kickstarter campaign can give you an answer. The C.H.I.P. is a loss leader to build a community. Once the C.H.I.P. is shipping, the community becomes the product. The low price point is a classic technique to build excitement for and a community around a project. There are hundreds of fully funded projects tucked away deep on Kickstarter that prove this point.
From a business perspective, the C.H.I.P Kickstarter doesn’t even make any sense. The original goal for the C.H.I.P. Kickstarter was only $50,000. If a business that is already shipping hardware can’t find an investor or take out a loan to cover the development of a new product, one of two realities are necessarily true: either the product is an impossible pipe dream that no investor or lender would consider, or Kickstarter itself is a marketing tool to build a community.
Next Thing Co. disagrees about Olimex’s $39 claim. In their latest campaign update, they say C.H.I.P. will still be $9 when pre-orders open up. As far as Next Thing Co. is concerned, they’re unfazed by the conjecture of their competitor. [Thomas Deckert] of Next Thing Co. says, “I can tell you there is at least one significant error in that post by Olimex.”
The basic idea of C.H.I.P. is to leverage off the shelf components – the kind you’d find in cheap Android tablets and value line smart phones – put them on a board, and get a Linux distro running. That’s the basic premise of the Raspberry Pi, and that’s the idea behind dozens of other single board computers available today. No company has ever done it for nine dollars. If you take them at their word, that’s what Next Thing Co. will be delivering. Exactly how they’ll be doing this is anyone’s guess, and once these tiny, cheap computers start shipping, we’ll probably learn a lot about supply chains and what’s actually available from those fabulous chip manufacturers. Until then, it’s anyone’s guess.
Filed under: Crowd Funding, Featured
Metal fabrication is a an art that often goes under appreciated. The ability to take common stock in the form of sheet, pipe (square or round), and in this case rod, and make it into anything is intoxicating for the artist and super villain inside of each of us. Recently [asciiArtVandaly] took on an interesting job and was thoughtful enough to make a photo album of the process. He literally created the world out of metal.
The build is a wire-frame globe. The latitude and longitude rods are rolled to the proper arc, but holding them in place is a bit of a trick. This image shows the welding jig built just for this project. It has large and small nobs to match the increasing spacing of the rods, with washers holding down ever other joint. If you want to see an example of rod-rolling check out the unrelated How It’s Made segment found after the break.
This jig is visually stunning to look at, but the math used to lay something like this out is only mildly interesting compared to the work done to add the continents to the piece. Each of these were cut out and then hand hammered to match the curve of the globe before being welded in place and outfitted with lighting for cities. That’s a skill you can’t get without a lot of practice — and get this, [asciiArtVandalay] does it as a hobby. Who knew robot engineers needed hobbies?
The finished globe is about eighty pounds of stainless steel. The build ends up being corporate art for a company sure to turn [Tyler Durden’s] eye.
Filed under: misc hacks
In the annals of hackerspace history, there’s one space that stands above the rest. It’s c-base, the crashed spaceship below Berlin that’s also one of the first hackerspaces in the world. Before NYC Resistor, Noisebridge, and every other building filled with tools and cool people, there was c-base.
Although the Hackerspace movement has only been around for a little less than a decade now, c-base itself is much, much older. It was founded way back in 1995, marking this year as the second decade of c-base’s existence. A few of the members of c-base are celebrating this occasion by publishing a book on the vast and storied history of their hackerspace.
The mythology of c-base includes a space station crashing in the middle of Berlin, with the giant, famous disco ball in Berlin being the station’s antenna. Yes, it’s weird, but all good hackerspaces have some sort of irreverent mythos surrounding them. The c-booc will document the twenty year long excavation of the space station, chronicling how this hackerspace came to be.
Filed under: Hackaday Columns, Hackerspaces
Now that summer is coming, it’s time to break out the Air Conditioners! There are some old AC units out there that still work just fine, but nowadays we are used to everything being remotely controlled and automatic. [Phil] had an old window-mounted AC unit that still worked but was installed in a not-so-convenient place. To access the AC’s controls, one would have to climb over a large desk. This is a perfect opportunity to use the plethora of widely available hobby electronics to make an automatic AC controller retrofit.
First things first, there needs to be a way to turn the current control knob on the AC. [Phil] modeled up a 3D bracket to hold an RC car servo to the AC control panel. Attached to the servo horn is a slotted cylinder sized appropriately to fit the shape of the control knob. An Arduino measures the temperature of the room via a DS18B20 temperature sensor which then has the servo turn the control knob to the appropriate position, on or off. The Arduino sends temperature data back to a PC via MegunoLink Pro which graphs past data and also displays current temperature data. Using MegunoLink Pro, the min/max temperature points can also be set without uploading a new sketch to the Arduino.
From the temp vs time graph, it looks like the room temperature stays a consistent 23 +/- 1 °C. [Phil] did us summer-swelterers a favor and made all his design files available. This is a great idea but wonder if leaving the air conditioner unit switch in the ‘on’ position and turning the unit on/off via a relay connected to the 120vac line would work just as well.
Filed under: home hacks
TI makes some great chips, and to sell those chips, they’re more than willing to put together some awesome tutorials, examples, and online classes to get engineers up and running. This isn’t limited to $5 Launchpads; TI has a great video and lab series for their precision OpAmps. These tutorials come with an evaluation module that costs about $200. Yes, that’s two Benjamins for a few OpAmps and a PCB. Of course no engineer would ever pay this; their job would. But what about someone who wants to learn at home?
That’s where [SUF]’s project for The Hackaday Prize comes in. He’s building a replica of a $200 lab board, and even without researching the cheapest solution for each individual component, [SUF] reckons he can build this kit for about $50. Like I said, the TI board is a business purchase.
The complete lab and tutorial TI offers uses NI’s virtual lab. This, again, isn’t something a random electron hacker could afford, but anyone who wants to go through this teaching module would probably use their own tools anyway.
As far as projects to teach electronics go, [SUF] has knocked it out of the park. He’s already relying on excellent tutorials, but bringing the price down to something a little more sane and amenable to checkbooks that aren’t tied to the corporate account.The 2015 Hackaday Prize is sponsored by:
Filed under: The Hackaday Prize
Okay so this IOT is getting a bit out of hand. Introducing the world’s first(?) tweeting, internet connected, lawnmower.
[Michel] recently bought one of those new-fangled cordless lawn mowers by EGO. It runs off a 56V lithium ion battery pack, and apparently, works pretty well. Since it has plenty of on-board power, he decided to strap a 64MHz PIC18F25K22 to a ESP8266 and connect it to the internet. That part number has been taking the world by storm and it’s totally freaking awesome. The ESP8266 is a tiny WiFi module that is controllable over a serial port — and it only costs $5. Hello IOT-everything.
Anyway, to avoid voiding his warranty, [Michel] using non-invasive sensors to collect data — A series of hall effect sensors and magnets to be exact. One detects when the cutting system is engaged, and another magnet and sensor pair counts wheel revolutions. In the end, this gives you data on how far you pushed the mower, how long you spent cutting, and how long you were out there. When the job is done, you have the option to push a tweet with your stats. Woo!
He does admit, the tweeting feature is more there just to annoy his friends.
Filed under: Arduino Hacks, tool hacks
When most people think of 3D printing, they think of Fused Deposition Modelling (FDM) printers. These work by heating a material, squirting it out a nozzle that moves around, and letting it cool. By moving the nozzle around in the right patterns while extruding material out the end, you get a part. You’ve probably seen one of the many, many, many FDM printers out there.
Stereolithography printing (SLA) is a different technique which uses UV light to harden a liquid resin. The Chimera printer uses this technique, and aims to do it on the cheap by using recycled parts.
First up is the UV light source. DLP projectors kick out a good amount of UV, and accept standard video inputs. The Mitsubishi XD221u can be had for about $50 off eBay. Some modifications are needed to get the focus distance set correctly, but with that complete the X and Y axes are taken care of.
For the Z axis, the build platform needs to move. This was accomplished with a stepper motor salvaged from a disk drive. An Arduino drives the motor to ensure it moves at the right rate.
Creation Workshop was chosen as the software to control the Chimera. It generates the images for the projector, and controls the Z axis. The SLA process allows for high definition printing, and the results are rather impressive for such a cheap device. This is something we were just talking about yesterday; how to lower the cost of 3D printers. Obviously this is cheating a bit because it’s banking on the availability of cheap used parts. But look at it this way: it’s based on older technology produced at scale which should help a lot with the cost of sourcing this stuff new. What do you think?
Filed under: 3d Printer hacks
Lava lamps had their time, but that time is over. Perhaps a spinning, glowing, DNA helix style lamp will take their place?
Inspired by the ever mesmerizing DNA helix, a member of the eLab hackerspace decided to try making it into a lamp. It’s almost entirely 3D printed, with the helix made out of glow in the dark filament. A series of UV LEDs fade in and out as a small geared motor from a microwave turntable spin the helix round and around.
[João Duarte] designed the assembly using TinkerCAD and has shared all the files on the Instructable in case you want to make one yourself. It is a lot of printing though, so you might want to recruit your own hackerspace’s 3D printer to do some of the work. He ended up using his own Prusa i3 as well as the LulzBot TAZ4 from the space to speed things up.
The end result is rather mesmerizing. We really like the glow in the dark touch.
[Thanks for the tip Hugo!]
Filed under: 3d Printer hacks, led hacks
Kerbal Space Program, the game that teaches engineers at JPL and SpaceX the basics of rocket design and orbital mechanics, recently had a giant update. There are now science contracts that require you to fly Kerbals all over their tiny globe, collect data, and transmit it back to the Kerbal Space Center. As would be expected, this is a grind for XP, and the contracts sometimes don’t make sense – you need to collect data from cliff faces and mountain tops. Landing a Kerbal jet at these places is hard.
[Matt Thiffault] wanted to do these science contracts more efficiently. The best way to get to a remote location without a landing strip would be a helicopter, but a harrier jump jet would do just as well. This isn’t supported in the stock game, so [Matt] wrote a complete control system for four engines to control a hovering Kerbal jet.
[Matt]’s work is built on kOS, a scriptable autopilot mod for Kerbal that was originally intended to be something like the Apollo Guidance Computer. People have been using it to make computerized skycranes and automated rendezvous and docking programs, but these are actually relatively simple examples; there’s far more math involved in flying a quadcopter than there is getting into orbit.
To build his automated hovering harrier, [Matt] needed an aircraft. His Kerrier has parts from the Kerbal Aircraft Expansion, B9, and Infernal Robotics mods for KSP, but this is only half the problem. Anyone can put four tilt jets on an airplane, and it takes a real wizard to force a control system to hover. Hover control of the Kerbal harrier is accomplished with a complete control system for a four-engined aircraft, with proper PID control loops and code updating at 20Hz.
With kOS, the proper plane, and the right software running on this emulated guidance computer, [Matt] is able to park his plane in mid-air, have a Kerbal descend the ladder, perform some science, and return to base. It’s an impressive amount of work for a video game. A good thing, too: [Matt] is looking to get into controls engineering professionally. Whether this will go on his resume is another question entirely.
Filed under: misc hacks
[Kevin] wanted a display where he could take a quick glance and get all the current environmental information he uses throughout the day. That information includes, of course, the time and date as well as weather information. We’re not just talking the current weather information but the forecast for the upcoming week as well as a map showing current weather patterns. To do this, [Kevin] came up with a unique system he’s calling the PiClock.
[Kevin] did some serious programming to get this clock project off of the ground. The weather data comes via the Weather Underground API and the map data from the Google Maps API. The main program is written in Python and will run on any OS running Python 2.7+ and PyQt4. If you’re interested in doing something similar, check out the source at github.
From the project’s name, it is no surprise that a Raspberry Pi is the brains here. A USB WiFi adapter allows access to the internet but an Ethernet connection would do just fine. Having the RaspPi hanging out with wires everywhere would be a little lazy, so [Kevin] opened up his 19″ LCD monitor and mounted the RaspPi inside the case. He tapped 5vdc off of the monitors power supply and used that to power the RaspPi, no external wall wart necessary! And if the PiClock’s background isn’t cool enough, some RGB LED strips were mounted to the back of the monitor to give an Ambilight effect.
Filed under: clock hacks, Raspberry Pi
It’s pretty much guaranteed that when working with small parts, you will drop at least one. This phenomenon is just how the universe works, there is no avoiding it. Digging though a carpet or dirty shop floor usually results in frustration and subsequent scrambling for a replacement part. Tired of crawling around on his knees looking for runaway parts, [Frank] decided to do something about it. He made a vacuum attachment that helps with the search… and it’s made from stuff he had kicking around the house.
The idea here is to suck up and contain the part without having it making it’s way into the vacuum. To do this there would have to be an intermediate chamber. For this, [Frank] used a multi-pack CD container. This was a great choice because it is clear, allowing him to see what enters the container, and it unscrews quickly making it easy to retrieve the tiny part. The inlet and outlet connectors are made from PVC and are attached to the CD container’s base with adhesive. To keep the debris from getting past the CD container, an old kitchen strainer was cut up and the screen material was used to only let air pass. Once a shop-vac is connected to the outlet pipe, the sucking can begin. [Frank] shows that he has to sift through a bunch of shop-floor crud to find his dropped screw, but it works!
Filed under: tool hacks
[ThatHpiGuy] had a problem. He wasn’t impressed with the performance from his kids’ electric-powered Mini. The 6 volt system was anemic at best, and was just begging for an upgrade. Pulling off the seat and checking the undercarriage, [ThatHpiGuy] realized the motor and gearbox were a perfect fit for the Turnigy 2300 Kv motor from his R/C short course truck. A couple of screws later, and he had the fastest ride-on toy on the block. Since this was a quick hack, [ThatHpiGuy] kept the truck’s R/C receiver, electronic speed control, and 2 cell LiPo power setup intact. The result is a cooperative system where he controls the throttle via R/C, and his kids control the steering.
That steering is still a bit of an issue though. Like many kid toys, the Mini only has one drive wheel, in this case the right rear. If [ThatHpiGuy] pours on the power a bit too quickly, the single wheel either spins or forces the car into a hard left turn. Aside from that, it looks like both [ThatHpiGuy] and his children are having a ball with this hack. The car will even pop a wheelie from a standing start! You’ve got to see it after the break.
Filed under: transportation hacks
There was a time when just about every computer – even laptops – came with a parallel port. That’s 25 pins of bit-banging goodness, accessible from every programming environment, that could control any random pile of electronics sitting on a desk. The days of parallel ports are behind us now, and if you want to blink a pin with a computer, you’re looking at controlling a microcontroller over USB or something.
[ajlitt]’s Tiny Bit Dingus is just that: a microcontroller stuffed into a USB plug with a few pin headers. With the right app, you can control these pin headers over USB. It’s the closest you’re going to get to a parallel port with modern hardware.
This bit dingus isn’t meant to replace the Bus Pirate, an Arduino, or anything else; it’s meant to be a small and simple way to connect random electronics to a computer with as few parts as possible. If you’re looking for a part to add to your electronic tinkerer everyday carry rig, this would be it.
There’s a few bits of interesting hardware inside the Bit Dingus. A while back, [ajltt] ran into the Freescale KL27, a Cortex M0+ that does USB without a crystal, has a USB bootloader, and doesn’t require many additional components at all. It’s the perfect size for the project at 5x5mm, and is unbrickable while still being flashable over USB.The 2015 Hackaday Prize is sponsored by:
Filed under: The Hackaday Prize
Skateboards are fun, but you have to do all that pesky kicking in order to get anywhere. That’s why [Nick] decided to build his own electric skateboard. Not only is the skateboard powered with an electric motor, but the whole thing can be controlled from a smart phone.
[Nick] started out with a long board deck that he had made years ago. After cleaning it up and re-finishing it, the board was ready for some wheels. [Nick] used a kit he found online that came with the trucks, wheels, and a belt. The trucks have a motor mount welded in place already. [Nick] used a Turnigy SK3 192KV electric motor to drive the wheels. He also used a Turnigy electronic speed controller to make sure he could vary the speed of the board while riding.
Next [Nick] needed some interface between a smart phone and the motor controller. He chose to use an Arduino Nano hooked up to a Bluetooth module. The Nano was able to directly drive the motor controller, and the Bluetooth module made it easy to sync up to a mobile phone. The Android app was written using MIT’s App Inventor software. It allows for basic control over the motor speed so you can cruise in style. Check out the video below for a slide show and some demonstration clips.
It’s a popular project, and eerily similar to the one we saw a couple months back.
Filed under: Arduino Hacks
We’ve been admirers of the work [Eric] and friends have been doing over at TubeTime for years. One of the earliest we can remember is the decatron kitchen timer, and we still tell the story of [Eric] purposely leaving out button debouncing in order to make his vector flappy bird even harder.
TubeTime is back at it this year and we had the opportunity to speak with them at Bay Area Maker Faire. The group specializes in working with old tube displays and this year’s offering was spectacular in many ways. First off, the software side of things is an emulator running on an STM32 F4 Discovery board. The chips on these boards have a pair of 12-bit DACs which are driving the X and Y of the vector displays. Code to run the original ROMs was ported from existing projects, but the audio for the games was kind of a hack to get working.
This particular display is where things get really fascinating. The tube itself was originally manufactured as test equipment for television repairmen. What’s fascinating about this is that [Eric] had to rewind the deflection yokes himself to get it working again. Luckily he documented quite a bit about his initial research into this process and his experiments to remedy some distortion issues he encountered once it was working.
Make sure to head on over to TubeTime and read their overview of the Battlezone machine. After the break we’ve also embedded a few of our own pictures as well as the interview at BAMF.
Filed under: Featured, video hacks
That’s right. [Colin Furze] just made a household appliance obsolete. Who needs a toaster when you can cut your bread… and toast it at the same time!
Leave it to [Furze] to make something out of the Hitchhiker’s Guide to the Galaxy a reality. Submitted as an idea by one of his subscribers to his new series called Furze’s Invention Show, he took it upon himself to make the long revered lightsaber bread knife. We were waiting for this day.
Unfortunately, it’s not exactly a light saber. In fact, its more of a light-saw-ber, which, pronounced with the right accent could be easily mistaken for the real deal. Using a re-wrapped microwave transformer — much like home-made spot welder rigs — [Furze] is pumping a ton of amps at low voltage through a hacksaw blade, making it red hot and ready to toast bread.
The build is pretty simple, but as always, very entertaining to see how he’s made it.
What will he think of next…
Filed under: tool hacks
Throughout their long history, American Machine and Foundry (AMF) have made forays into many areas of automation. And as the American cultural landscape of the 1950s and ’60s shifted toward fast, cheap, and convenient foodstuffs available for consumption inside of spacious, finned automobiles, AMF was there with AMFare, an (almost) completely automated system for taking orders, preparing food, and calculating bills.
AMF named the system “ORBIS” after its two main functions, ordering and billing. But ORBIS was not completely autonomous. A human operator received orders from a table-side telephones inside the restaurant and intercoms used by drive-in customers, and entered them on an enormous console. Orders were routed to several machines to prepare the food, cook it, and package it in various ways. We witness the odyssey of the burger in complete detail, from punching out perfect patties to their final, plastic-wrapped form.
Surprisingly, the AMFare selection wasn’t limited to delicious burgers, fries, and milkshakes. It could crank out sixteen different menu items, and do so pretty quickly. In the space of one hour, AMFare could produce more than 400 burgers, over 350 orders of fries, or about 700 milkshakes. Even so, collating the orders required human intervention. We imagine that the awful task of cleaning all that expensive Rube Goldberg-esque machinery did, too.
Thanks for the tip, [Gregg]!
Photo credit (both): Harvard Art Museums/Fogg Museum, Gift of Barbara Robinson
Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.
Filed under: Hackaday Columns, Retrotechtacular
With Arduino library support on an ARM Cortex M4 processor, it’s no surprise that we’re fans of the Teensy 3.1. And lately, [Paul Stoffregen] has been building out the Audio Library for this platform, making it even more appealing to the synth / audio geeks among us. And now, with just the addition of a highfalutin LED and some software, the Teensy can output digital audio over optical fiber.
S/PDIF, and more specifically optical TOSLINK, uses LED light sent down an optical fiber to encode audio data. The advantage of this over any voltage-level signals (like with regular wires) is that the source and destination devices aren’t electrically connected at all, which gets rid of the dreaded ground loop hum and any RF interference.
An S/PDIF audio data stream is a bit complex, but if you’re interested [Micah Scott] has a fantastic dissection of it up on her blog. Of course, you don’t have to know anything about any of that to simply use S/PDIF with the Teensy Audio Library.
We love open source hardware and software because of the collaborations that make ultra-rapid development of niche stuff like this possible. You can follow along with the development of the Teensy’s S/PDIF capabilities on the PJRC forum. Contributor [Frank B] modestly claims that “everything was already on the internet”, but that doesn’t make it any less cool that they got from zero to working library in a few weeks. (And note the clever use of a precomputed lookup table for speed.)
On the hardware side, [Paul] has posted up his adapter board for a cheap, but very professional looking, optical TOSLINK sender. But if you’re feeling ghetto, you can simply use a red LED pointed just right into the optical cable.
The end result? Lossless transmission of CD-quality audio from an Arduino-esque microcontroller, sent on a beam of light, for less than the cost of a latté.
Filed under: ARM, home entertainment hacks, peripherals hacks