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ถูกปรับปรุง 41 sec ก่อน

Serial Surgery Saves Wacom Tablet from Landfill

37 min 14 secก่อน

Years ago, [Greg] got a Wacom Artpad II graphics tablet through Freecycle. What’s the catch, you ask? The stylus was long gone. When he found out how expensive a direct replacement would be, the tablet was laid to rest in his spare parts box. Fast forward a few years to the era of the phone-tablet hybrid and [Greg]‘s subsequent realization that some of them use Wacom stylii. Eight bucks later, he’s in business, except that the tablet is serial. Wacom no longer supports serial tablets, so he had to convert it to USB.

With the help of the WaxBee project and a Teensy 2.0, he would be able to emulate an Intuous2 tablet by sniffing and re-encoding the packets.  Things got a little hairy when he went under the hood to remove the ADM202 TTL-to-RS232 chip with a Dremel—he accidentally gouged some of the pads it sat on as well as a few of the traces. Feeling frustrated, [Greg] took some high-res pictures of the board and posted them to a message board. As it turns out, those pictures helped him recreate the traces and get the tablet running. A little big of glue and tape later, he was in business. [Greg] even gave himself access to reprogram the Teensy.

Filed under: tool hacks

Solving Arduino’s stk500_getsync() error

3 hours 37 minก่อน

[psgarcha] took a year-old Arduino Uno on an international trip and upon returning found something was wrong. Every time he would try to upload, he would get the dreaded avrdude error, ‘stk500_getsync(): not in sync resp=0×00′. The Rx light would blink a few times during the attempted upload, but the tx light did not. Somehow, something was terribly wrong with the ‘duino, and [psgarcha] dug deep to figure out why.

To test the quality of the Arduino’s serial connection, [psgarcha] performed a loopback test; basically a wire plugged into the Tx and Rx pins of the Arduino. Sending a short message through the serial port showed the problem wasn’t the USB cable, the ATmega16u2 on the ‘duino, or any traces on the board. This would require more thought.

The main reason for the error would then be no communication between the computer and the ‘duino, the wrong COM port selected, the wrong board selected in the Arduino text editor, or timing errors or a corrupt bootloader. The first three errors were now out of the question, leaving timing errors and a corrupt bootloader. Troubleshooting then moved on to ordering a new programmer, and still this didn’t work with the broken Uno.

Frustrated with one of the greatest failures to become an Arduino tinkerer, [psgarcha] took a good, long look at the Uno board. He glanced over to an Arduino Mega board. Something looked different. On the Uno, the resonator had blown off. Problem found, at least.

Replacing the blown part with a hilariously large can crystal oscillator, [psgarcha] was back in business. This isn’t how you would fix 99% of getsync() errors, and it’s difficult imagining a situation where a this part would randomly blow, but if you’re ever looking at a nearly intractable problem, you need to start looking at what really shouldn’t fail.

Awesome rework, though.


Filed under: Arduino Hacks, repair hacks

Cloning a Board from Pictures on the Internet

6 hours 36 minก่อน

[Andrew] was a pretty cool guy in the early 90s with an awesome keyboard synth that did wavetable synthesis, sampling, a sequencer, and an effects processor. This was a strange era for storage; a reasonable amount of Flash memory was unheard of, and floppy disks ruled the land. [Andrew]‘s synth, though, had the option to connect SCSI drives. Like all optional add ons for high-end equipment, the current price for the Ensoniq SCSI card is astronomical and [Andrew] figured he could build one of these cards himself.

Poking around eBay, [Andrew] found the card in question – just a few passives, some connectors, a voltage regulator, and an odd chip from AMD. This chip was a 33C93A, a SCSI controller, and a trip down the Chinese vendor rabbit hole netted him one for $7. Can’t do better than that.

With the datasheet for the chip in hand and a few reasonable assumptions on how the circuit worked, [Andrew] tried to figure draw the schematic. After doing that, he found another hobbyist that had attempted the same project a few years earlier. All the nets were identical, and all that was left to do was sending a board off to the fab.

A quick trip to Front Panel Express got [Andrew] a mounting bracket for the card, and after plugging it in to the synth revealed a new option – SCSI. It worked, and with an ancient SCSI CD-ROM drive, he had boatloads of offline storage for his synth. Great work, and something we’d love to see more of.


Filed under: classic hacks, musical hacks

Five Dollar RF Controlled Light Sockets

เสาร์, 11/22/2014 - 22:00

This is tens of thousands of dollars worth of market research I’m about to spill, so buckle up. I have a spreadsheet filled with hundreds of projects and products that are solutions to ‘home automation’ according to their creators. The only common theme? Relays. Home automation is just Internet connected relays tied to mains. You’re welcome.

[Todd] over at Fabricate.io found an interesting home automation appliance on Amazon; a four-pack of remote control light sockets for $20, or what we would call a microcontroller, an RF receiver, and a relay. These lamp sockets are remote-controlled, but each package is limited to four channels. Terrible if you’re trying to outfit a home, but a wonderful exploration into the world of reverse engineering.

After cracking one of these sockets open, [Todd] found the usual suspects and a tiny little 8-pin DIP EEPROM. This chip stores a few thousand bits, several of which are tied to the remote control. After dumping the contents of the EEPROM from the entire four-pack of light sockets, [Todd] noticed only one specific value changed. Obviously, this was the channel tied to the remote. No CRC or ‘nothin. It doesn’t get easier than this.

With the new-found knowledge of what each lamp socket was looking for, [Todd] set out to clone the transmitter. Tearing this device apart, he found a chip with HS1527 stamped on it. A quick Googling revealed this to be an encoder transmitter, with the datasheet showing an output format of a 20-bit code and four data bits. This was a four-channel transmitter, right? That’s where you put each channel. The 20-bit code was interesting but not surprising; you don’t want one remote being able to turn of every other 4-pack of lamp sockets.

With all the relevant documentation, [Todd] set out to do the obvious thing – an Arduino transmitter. This was simply an Arduino and a transmitter in the right frequency, loaded up with bit of carefully crafted code. [Todd] also figured out how to expand his setup to more than four lamp sockets – by changing the 20-bit code, he could make his Arduino pretend to be more than one transmitter.

With Arduino-controlled lamp sockets, the world is [Todd]‘s oyster. He can add Ethernet, WiFi, Bluetooth LE, and whatever trendy web front end he wants to have a perfect home automation setup. It’s actually a pretty impressive build with some great documentation, and is probably the cheapest way to add Arduino/Internet-enabled relays we’ve ever seen.


Filed under: home hacks, radio hacks

Creating a Scanning Monochromator

เสาร์, 11/22/2014 - 19:00

If you need a specific wavelength of light for research purposes, the naïve way of obtaining that is a white source light, a prism, and a small slit that will move across your own personal Dark Side of the Moon album cover. This is actually a terrible idea; not only won’t you have a reference of exactly what wavelength of light you’re letting through the optical slit, the prism itself will absorb more of one wavelength of light than others.

The solution is a monochromator, a device that performs the same feat of research without all the drawbacks. [Shahriar] got his hands on an old manual monochromator and decided to turn it into a device that performs automatic scans.

The key of a monochromator is a diffraction grating, a mirrored surface with many fine parallel grooves arranged in a step pattern. Because of the surface of the diffraction grating, it’s possible to separate light according to its spectrum much like a prism. Unlike a prism, it’s effectively a first surface mirror meaning all wavelengths of light are reflected more or less equally.

By adding a stepper motor to the dial of his monochromator, [Shahriar] was able to automatically scan across the entire range of the device. Inside the monochromator is a photomultiplier tube that samples the incoming light and turns it into a voltage. By sampling this voltage and plotting it with MATLAB, [Shahriar] was able to plot the intensity of every wavelength of light within the range of the device. It’s all expertly explained in the video below.

Filed under: tool hacks

hack.summit(); // a virtual dev conference

เสาร์, 11/22/2014 - 16:00

If you’d like to spend four days learning from and picking the brains of a big group of well-known developers and open-source wizards for the low, low cost of absolutely free, keep reading.

The hack.summit() conference is a live, global event put on by the  fine folks behind real-time programming assistance service hack.hands(). From December 1 to December 4, a wide range of speakers will present and answer democratically popularized questions over Crowdcast via Google+ Hangouts. Speakers in attendance include wiki inventor and Design Patterns pioneer [Ward Cunningham], Codeacademy founder [Ryan Bubinski], Google Glass creator [Tom Chi], Python Software Foundation’s [Alex Gaynor], and even the inimitable [Jon Skeet].

The goals for this conference are simple and admirable: to educate developers of all stripes about best practices, to encourage mentorship in the programming community, and to spread the joy of coding by supporting coding non-profits.

You can register for free simply by spreading the word through social media, but making a donation to the coding non-profit of your choice is definitely encouraged. There are many to great organizations to choose from such as  CoderDojo (an easy choice for us). A tidy summary of the event is available at the hack.summit() FAQ(PDF).

Filed under: cons

A Modern Woodworking Workbench

เสาร์, 11/22/2014 - 13:00

This is a post about workbenches, but not the benches you’re probably thinking about. Workbenches meant for electronics development are simple matters – just about any flat surface, a few shelves for equipment, and an anti-static mat will be fine for every conceivable use.  Workbenches for woodworking are a separate matter entirely. There’s actually quite a bit of history behind the development of the woodworking workbench, but the basic idea is a thick laminated wood top, integrated vices, holes in the work surface for bench dogs, and ergonomics that allow for comfortable use of hand tools. The basic design of these benches hasn’t changed much in several hundred years, and [Dirk] thought the design was ready for a modern update.

Yes. This one moves on its own. It’s a robotic woodworking workbench that lifts the workpiece and table up to a comfortable position. The lifting mechanism is a quartet of Acme threaded rods all powered by an Arduino-controlled stepper motor linked together with sprockets and chain. There’s a remote control to raise and lower the bench, and a few batteries tucked behind the mechanics to allow for off-grid operation.

A bench must be sturdy, and this one has clamps on the frame of to clamp the ‘elevator car’ securely to the bench. Leveling casters make this bench mobile, giving [Dirk] the ability to move it around the shop, or from site to site. An integrate face vise and a twin-screw end vise securely hold the workpiece to the table, and a linseed oil finish make scratches and gouges easily repairable.

The majority of the frame is constructed out of birch plywood cut on a CNC, so if you have a Shopbot or other large router available to you at the local hackerspace, building this bench for yourself is a much simpler matter than the mortise and tenon joinery of a more traditional woodworking workbench. If you end up building this bench, be sure to pick up the casters [Dirk] used; this thing weighs 800 pounds. Massive, heavy, and an excellent bench that can be passed down to your grandkids. Video below.

Filed under: Arduino Hacks, tool hacks

Upgrading a Laminator for Toner Transfer PCBs

เสาร์, 11/22/2014 - 10:00

If you need a circuit board now, you’re probably looking at a toner transfer process; all you need to make a PCB is a copper clad board, a laser printer, some special paper, and the usual etching chemicals. The quality of these boards is highly dependant on the quality of transferring toner to the copper, and getting the process right is as much an art as it is a science. A clothes iron is the easy way of transferring the toner to the board, but if you’re looking for repeatability, you’ll probably want a laminator.

Laminators, too, also vary in quality. The king of toner transfer laminators is the Apache AL13P. With four heated rollers and a steel chassis, it’s enough to do some serious heating. [mosaicmerc] came up with an amazing mod for his Apache laminator that takes all the guesswork out of the settings, and does it all in one pass for maximum repeatability and PCB quality.

The Apache laminator in question is a beast of a machine that drives four rollers with a synchronous motor and also has a ‘reverse’ button that sends the laminations out the front end of the printer. Stock, a toner transfer PCB would require dozens of passes through the Apache, but [merc]‘s mod takes care of everything for you.

The addition that makes this possible is a small board with a PIC12 microcontroller. This microcontroller connects the motor driver board and the display interface together, triggering the reverse button to move the board 5/8″ forward and 1/2″ back, giving the laminator an effective speed reduction of 12:1. This method also has the bonus of not tampering with the motor or control circuitry, and allows for multiple passes in the same run.

With this modification, the Apache AL13P becomes the perfect solution to transferring toner to a piece of copper, with the ability to transfer 10mil traces on 1oz copper. The board also offers some other features like thermal sensor failure shutdown and a cool-down mode that overrides the heater. If you’re looking for an easy way to step up your toner transfer PCBs, you can’t do much better than this mod.

Filed under: tool hacks

We’re Hiring

เสาร์, 11/22/2014 - 07:01

The Hackaday crew has done some amazing things this year, and we’re finding ourselves a bit stretched. Want to lend a hand while making some extra dough to plow back into your projects? This is a work-from-home (or wherever you like) position that affords you the opportunity to guide what we cover on Hackaday.com. We hire writers for their judgement, which helps keep our subject matter fresh. But don’t worry, we do have a very active tips line from which many of our story leads come.

Contributors are hired as private contractors and paid for each post. You should have the technical expertise to understand the projects you write about, and a passion for the wide range of topics we feature. If you’re interested, please email our jobs line and include:

  • Details about your background (education, employment, etc.) that make you a valuable addition to the team
  • Links to your blog/project posts/etc. which have been published on the Internet
  • One example post written in the voice of Hackaday. Include a banner image, 150 words, the link to the project, and any in-links to related and relevant Hackaday features.
Words of encouragement

First off, we won’t be discussing compensation publicly. Want to know what we pay? Send in a successful application and we’ll talk about it.

Secondly, don’t pass up this opportunity. I watched one of these posts go by and waited another year before I saw the next one and applied. Now I’m running the place. Our team is made up of avid readers. If you’re passionate about the stuff you read here and you have a few hours each week to do some writing you need to apply now!

So what are you waiting for? Ladies and Gentlemen, start your applications!

Filed under: Featured

3DS Homebrew Channel and Custom Firmware

เสาร์, 11/22/2014 - 04:00

Nintendo has always been very wary about allowing independent and homebrew developers making games for their consoles, and the 3DS is no exception. It’s locked down, and a few 3DS and console hackers have spent years searching for a method that will easily allow anyone to run unsigned code. That day is finally here. The exploit is called NINJHAX, and it allows anyone to install the Homebrew Channel, the repository for everything awesome in the world of 3DS homebrew development.

The latest exploit relies on a bit of code in a retail game – Cubic Ninja – to run unsigned code. This game includes a level editor that allows players to share different levels by QR codes and 3DS’ camera. By carefully crafting one of these QR codes, the 3DS gains the ability to run the Homebrew Channel

If this exploit sounds familiar, you’re right. The most common way to open up a Wii for homebrew development is Smash Stack, an exploit found in Super Smash Bros. Brawl. This exploit also works by modifying custom stages, and opened the door to a wealth of homebrew development for the Wii.

In the video below, [smea] shows off his exploit by starting Cubic Ninja, going to the QR code level editor, then loading up homebrew games. A copy of the game that enables this exploit, Cubic Ninja, is required for this exploit. Last week, you could buy Cubic Ninja for a few dollars on eBay and Amazon. Today, the price has settled around $50, with a few very dumb or very eager people paying up to $300. If you already have the game, you’ll only need to get the homebrew starter kit, generate a QR code, and start installing unsigned code. All the instructions are available on [smeal]‘s site.

Because this exploit gives anyone with a hacked DS full run-time control, almost anything that can be done with a 3DS is possible, including very easy piracy. [smea] realizes there are ethical problems with this, and really only wants the ability to get his own code running on a device he’s paid for. To ease his mind, [smea] is releasing an exploit that will only allow user mode ARM11 code. Anyone wanting to pirate the entire 3DS library will have to wait a few days until another team releases a more capable exploit based on [smea]‘s work.



Filed under: nintendo ds hacks, nintendo hacks

Hacklet 23 – The Groove Tube

เสาร์, 11/22/2014 - 01:01

The transistor may rule the electronics world today, but before solid state moved in, vacuum state was king. Tubes, or valves if you’re from Europe, were the only way to fly. Every good hacker knew their triodes from their tetrodes and their pentodes. While technology has moved on, some hackers keep the past alive with tube based projects. This week on the Hacklet, we’re featuring some of the best tube projects on Hackaday.io!

We start with [256byteram] and Tube Television Tennis. [256byteram] is building an entire Pong style game from tubes, including a CRT to display the game. Displaying anything on a standard television means generating lots of timing signals. [256byteram] is doing this by using multivibrators to create one-shots and flip-flop circuits. Tube Television Tennis is still a work in progress, but [256byteram] already can display a paddle and move it around the screen in both X and Y. This project has already blown our minds!

From [Marcel] comes this great Low Voltage All-Tube Amplifier, which we featured on the blog earlier this year. [Marcel] does tubes without the danger of high voltage by using the ECL82 tube at 40 volts. The ECL82 incorporates both a triode pentode in one package, making it something of an integrated circuit. Power is provided by transformer while a PY88 tube handles rectifier duties, making this truly an all tube amp. A few passive components complete the design. We can’t wait to fire one up and hear some class A goodness while basking in the warm glow only a tube can create.

No tube article would be complete without some nixies, and [opeRaptor] is here to provide them with Obsolete Time, a nixie tube clock! Obsolete Time uses IN-12 Russian nixie tubes, and goes for a minimalist design. Under the hood it’s all modern tech though, including a Bluetooth radio which allows the clock to be set via an Android app.

[Brandon Foltz] is also getting into a vacuum state of mind as he takes Adventures in Hybrid Headphone Amps. [Brandon] is mixing the best of the old and new worlds by using a 6247 tube as the input stage to an LM386 single chip amplifier. This hybrid is still a work in progress, as [Brandon] is trying to clean up the sound from his LM386.

Hackaday.io update!

Did you know that we’re constantly upgrading Hackaday.io? We listen to your input on the feedback project, and we’re always adding new features to the site. If you haven’t noticed, you can now send private messages to other users. We’re sure this will help put users in contact with each other, so they can collaborate on even more projects! On the left side of each profile page there is a “Send a private message” button below the hacker’s avatar. You now have better indicators when you have messages or updates too! The private messages and feed icons at the top right of every .io page now have indicators to show how many messages or feed entries you have waiting. These are all based on live data, so they’ll update as you browse the site.

That’s all the time we have for this week’s Hacklet! As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Filed under: classic hacks, Hackaday Columns

Artisanal Vacuum Tubes: Hackaday Shows You How

ศุกร์, 11/21/2014 - 22:01
Homemade Vacuum Tube

About a decade ago I started a strange little journey in my free time that cut a path across electronics manufacturing from over the last century. One morning I decided to find out how the little glowing glass bottles we sometimes call electron tubes worked. Not knowing any better I simply picked up an old copy of the Thomas Register. For those of you generally under 40 that was our version of Google, and resembled a set of 10 yellow pages.

I started calling companies listed under “Electron Tube Manufacturers” until I got a voice on the other end. Most of the numbers would ring to the familiar “this number is no longer in service” message, but in one lucky case I found I was talking to a Mrs. Roni Elsbury, nee Ulmer of M.U. Inc. Her company is one of the only remaining firms still engaged in the production of traditional style vacuum tubes in the U.S. Ever since then I have enjoyed occasional journeys down to her facility to assist her in maintenance of the equipment, work on tooling, and help to solve little engineering challenges that keep this very artisanal process alive. It did not take too many of these trips to realize that this could be distilled down to some very basic tools and processes that could be reproduced in your average garage and that positive, all be it rudimentary results could be had with information widely available on the Internet.

Easy enough to make in your garage

Here is a typical construction process I utilize in my garage. I would like to point out that these processes include glass, thin metal, mica, and sharp tools that all represent cut hazards. Additionally extreme temperature in the form of hand torches, and R.F. induction bombardment are utilized. With all industrial processes extreme care must be taken in any endeavor. I would also like to point out that no mercury or other harmful materials are used in any of these processes. The primary materials are Glass, Nickel, Mica sheet, and tungsten wire. I.P.A and acetone are used as cleaners and a very small amount of barium is used in the getter.

Nearly all connections within a tube are of a welded variety, and spot welding is the quickest and most economical. I simply modified a cheap store-bought spot welder to accept small diameter welding rods and used a 10 amp Variac to control weld temperature. I connected a spring loaded board to use as a make shift jaw closer pedal.

Above on the right is a typical weld. I use Nickel as it has favorable properties for both vacuum use, and tube electronic characteristics. It also is easy to weld and does not oxidize readily under welding conditions in air, as long as the weld time is kept to a minimum. Also shown here is an exothermic evaporable getter ring. This contains a barium/aluminum alloy that evaporates by applying an induced R.F. heating field and adsorbs gas after the tube has been sealed to maintain a reasonable vacuum level.

To the left is what is called a Cage, with one half of the anode not yet attached. The entire structure is composed of Nickel sheet, wire, and mesh. .015 Clear mica, sheared to shape by a standard office scissor shear is punched by means of an arbor press, a block of wood, and a small steel pin. The anode is a sheet of .010″ Nickel formed around a small block of wood. The grid is made of soft temper nickel mesh that has been formed around a block, and welded to two nickel rods for support. Traditionally Molybdenum or nickel plated steel would be used for grid wires, but both materials are hard to work with and weld without special tools. To the right is the completed assembly with the second half of the anode welded to complete the cage.

 Putting it all together

Here the Cage has been welded to what is called the Stem and this is turn is called a Mount. The stem is the portion that contains the hermetic glass to metal lead seals and the exhausting tubeulation for connecting the tube to the vacuum system. This particular tube uses a commercially available Stem. They can be made by hand, however is is very difficult to get good results that hold up to use. This is the most demanding and critical part in the tube and there are many electronics glass manufacturers in the U.S. who can provide these parts to drawing, and those who wish to hand craft their own would do well to watch the YouTube videos of Ron Soyland who covers the topic. The tungsten filament is also threaded through the cage and spot welded to the stem leads at this point. This tube uses .0085 diameter 1.5% thoriated tungsten.

Here the fit of the Mount to the glass bulb is checked. The mica spacers should come in contact with the glass bulb to minimize vibration in the cage. The next step is to trim the excess bulb material and seal the bulb and mount together. This is done by placing these parts in a specially made lathe with two headstocks that turn in unison. Many shops would have made their own machines as I have done myself. However, in this picture I am using a commercially available Lathe.

Avoiding breakage from thermal shock

In large-scale production, carousel style sealing machines were typical. Generally you would anneal the tube after sealing. Sometimes you can flame anneal the glass without the use of an oven, but this is something that can only come with practice and experience. A better solution is to use borosilicate glasses. These types have greater resistance to thermal shock and are much easier to work with. Unfortunately they are far more expensive as they are typically reserved for extreme use. Large transmitting tubes and vapor style lights typically contain these sorts of glasses to handle extreme temperature variation and not damage the hermetic metal lead in seals.

Evacuation of the tube

The tube is placed into the vacuum system. This image shows a typical compression port containing a compressible gland. A high vacuum pumping system contains a mechanical rotary vane pump backing either an oil vapor diffusion pump or a turbo molecular pump followed by a refrigerated trap, and then the manifold the tubes are connected to. This will also typically contain a Ionization gauge, pictured on the upper portion of the picture. The analog gauge indicates fore pressure on the diffusion pump. Typically diffusion pumps require a fore pressure of 100 Millitor or micron to begin pumping action. One micron equates to 1.32 X 10-6 atmospheres of pressure. The ultimate pressure of a well built single stage diffusion pump with no leaks and a refrigerated trap is well below 1 X 10-7 TORR.

In vacuum tube practice however this is difficult to reproduce and only attainable in very small batches with long bake out times and extreme care. In large volume production if the actual pressure in the tube at tip off (The melting of the exhaust tube and removal from the pump) occurs at a pressure in the 10-4 range it is considered a good vacuum. It is then the responsibility of the barium getter to attain the final operating vacuum level. Higher levels of vacuum require more pumps and better practices than can be covered here.

Pumped tube waiting to have a base installed

The skilled do it yourselfer need not fret. It is possible to have acceptable results for experimental tubes using only a dual stage mechanical rotary vane pump with a refrigerated trap. However, care must be taken that every attempt is made to outgas the tube with R.F. bombardment and baking out the tube in an oven placed over it while on the pump for about an hour at more than twice the expected operating temperature. Your final pressure at seal off should be kept to below 20 micron and a large volume of getter material should be used. Additionally the tube should be flooded with nitrogen or argon gas and heated prior to evacuation to reduce the average quantity of oxygen in the tube. Many of the very first amplifier tubes were of this type. The resultant tube will emit, but ionization current will occur as the anode voltage increases. Typically this sort of “Soft” tube has an upper voltage range of 60 to 90 volts. As soon as a vacuum system is on and the tube being pumped is known to be leak free, the filament is lighted and remains lighted through the remainder of the exhaust process. This keeps gas molecules liberated from other metal parts from condensing on the filament and adds additional heat to remove gas from other surfaces. Shown to the left of the tube is a coil for R.F. induction heating of the internal metal components of the tube while on the pump. This also serves as the heat source to flash the getter, producing the mirrored surface and maintain a proper vacuum pressure. Generally a receiving tube will operate in the 1X10-6 range after the getter has had a chance to sorption the remaining gas in a commercially produced tube.


You have to remember that in the early days of electronics many of these processes were developed by observation of empirical evidence. It was several years before a serious scientific study of thermionic emission was begun in earnest and many important discoveries in the production of these devices were made by individuals working with little more than basic tools. Some of these discoveries were made purely by accident. There is no particular reason one cannot simply pick up where the innovators of the teens and twenties left off before tubes became big business. Don’t forget, Menlo Park was nothing more than a ramshackle building, and [de Forest] labored in a dark corner of Federal Telegraph when he developed the Triode. The particular type of tube I build is defiantly crude. Its max plate current is only a few milliamps, it’s gassy, and its gain is pitiful, but it works. It’s a reminder that at one time somebody tried something, they were not really sure how to do it and they had no solid plan of how, but they succeeded. They found a way forward and eventually crafted an entirely new area of science an industry. I think I will go play around in my garage a bit more now.


There are a few videos and websites on the net that show in excellent detail some of the finer points of tube production.

About Charles Alexanian

Charles is production manager at Alex-Tronix and also in charge of new product development, but he gets bored easily so he moonlights at M.U. Incorporated fixing vacuum pumps and tube test gear. He is also an on call technician for the most downloaded podcast on earth and several recording studios because he hates free time… I mean he really hates it. If he were to ever actually have any free time he would most certainly consume it in one of his many hobbies like: more electronics projects, prospecting, or HAM radio.

Filed under: classic hacks, Featured, radio hacks, slider

Tweet Messages from Punch Cards

ศุกร์, 11/21/2014 - 19:00

It all started with a conversation about the early days of computing. The next thing he knew, [Tim Jagenberg's] colleague gave him a stack of punch cards and a challenge.  [Tim] attempted to read them with a mechanical contact and failed.  Undeterred, he decided to make a punch card-to-keyboard interface using optical parts from disassembled HP print stations.  Specifically, he took apart the slotted optical interrupter switches to use their IR-LEDs and photo-transistors. Next, [Tim] drilled holes into two pieces of plastic, gluing the LEDs on one piece of plastic and the photo-transistors on the other. The photo-transistors tell the Teensy 3.1 whenever a hole is detected.

[Tim] developed an interpreter on the Teensy that reads the punch card according to IBM model 029 keypunch codes. The Teensy enumerates as a USB keyboard when connected to a computer. As a punch card is read, the Teensy outputs the decoded characters as key presses.  When a punch card has been completely read, an ‘Enter’ key press is transmitted.  Tweeting the punch cards is no more complicated than typing the text yourself. Naturally, the first message posted on Twitter from the stack of punch cards was “Hello World!”  [Tim's] binary and source code is available for download on Github.

We’ve enjoyed covering the backstory of the punch card and a previous project reading these cards using a digital camera setup. It’s always interesting to see the clever ways people use current technology and can-do attitude to read data from obsolete systems that would otherwise be lost.  We wonder what is on the rest of those punch cards?  Let’s hope [Tim] has more punch card tweets soon!

Filed under: classic hacks, computer hacks

Speaker Cabinet Boom Box Build

ศุกร์, 11/21/2014 - 16:01

When you get that itch to build something, it’s difficult to stop unless you achieve a feeling of accomplishment. And that’s how it was with [Rohit's] boombox build.

He started out with a failing stereo. He figured he could build a replacement himself that played digital media but his attempts at mating microcontrollers and SD cards was thwarted. His backup plan was to hit DX for a cheap player and he was not disappointed. The faceplate he found has slots for USB and SD card, 7-segment displays for feedback, and both buttons and a remote for control. But this little player is meant to feed an amplifier. Why buy one when you can build one?

[Rohit] chose ST Micro’s little AMP called the TDA2030 in a Pentawatt package (this name for a zig-zag in-line package is new to us). We couldn’t find stocked chips from the usual suspects but there are distributors with singles in the $3.50-5 range. [Rohit] tried running it without a heat sink and it gets hot fast! If anyone has opinions on this choice of chip (or alternatives) we’d love to hear them.

But we digress. With an amp taken care of he moved onto sourcing speakers. A bit of repair work on an upright set got them working again. The bulky speaker box has more than enough room for the amp and front-end, both of which are pretty tiny. The result is a standalone music player that he can be proud of having hacked it together himself.

Filed under: digital audio hacks

DIY Head Mounted Display Based On Movie Based On Stephen King Story

ศุกร์, 11/21/2014 - 13:01

Ever since [will1384] watched “The Lawnmower Man” as a wee lad, he’s been interested in virtual reality. He has been messing around with it for years and even had a VictorMaxx Stuntmaster, one of the first available head mounted displays. Years later, the Oculus Rift came out and [will1384] wanted to try it out but the $350 price tag put it just out of his price range for a discretionary purchase. He then did what most of us HaD readers would do, try building one himself, and with a goal for doing it for around $100.

The main display is a 7″ LCD with a resolution of 1024×600 pixels and has a mini HDMI input. Some DIY head mounted display projects out on the ‘web use ski goggles or some sort of elastic strap to hold the display to the wearer’s head. [will1384] took a more industrial approach, literally. He used the head mounting system from a welding helmet. This not only has an adjustable band but also has a top strap to prevent the entire contraption from sliding down. Three-dimensional parts were printed out to secure the LCD to the welding helmet parts while at the same time creating a duct to block out external light.

Inside the goggles are a pair of 5x Loupe lenses mounted between the user’s eyes and the LCD screen. These were made to be adjustable so that the wearer can dial them in for the most comfortable viewing experience. The remote mounted to the top strap may look a little out-of-place but it is actually being used to capture head movement. In addition to a standard wireless remote, it is also an air mouse with internal gyroscopes.

Filed under: Virtual Reality

Open-Source Laser Shooting Simulator

ศุกร์, 11/21/2014 - 10:00

Looking to practice your marksmanship skills at home? Check out the homeLESS (Home LasEr Shooting Simulator), an open-source tool for marksmanship practice. [Laabicz] developed this system as a cheaper alternative to commercial laser shooting simulators, which are just as simple but very expensive.

[Laabicz]‘s simulator primarily uses modified airsoft pistols that are fitted with batteries (installed in the magazine) and a laser in the chamber. Any gun can be used with the system as long as you can figure out how to attach a laser and trigger switch. To power the laser, a small capacitor is charged from batteries when the trigger switch is off. Once the trigger is pressed, the capacitor discharges through the laser and makes a short pulse of light.

The simulator is written in Processing and requires a projector and a webcam. The Processing sketch projects configurable moving targets on a screen or wall, and the webcam detects when a laser is triggered over any of the targets. The software supports multiple target types (including moving targets) and is quite configurable. Check out the video after the break to see the system in use.

Filed under: misc hacks

Hello Kitty Night Light Gets Flashy Upgrades

ศุกร์, 11/21/2014 - 07:01

See something in the world that sucks? As a person with hacker prowess, you view this sucky thing as a challenge to come up with an improvement and in some cases, an improvement that extends beyond what’s truly necessary but is just plain cool. This is what maker and father [Dan McDougall] did with his daughter’s light projecting Hello Kitty pillow.

As a thing whose one purpose was to shine bright starry patterns on a child’s wall at night, the pillow failed miserably. [Dan] Wondered why his daughter’s toy couldn’t live up to reasonable expectations all while sucking batteries dry, so he opened the large pink plastic casing in the center of the pillow to find a rather minimal board driving three very dim LEDs. The LEDs that faded on and off to create mixtures of different colors weren’t even red, green and blue either. The makers of the toy used yellow instead of the slightly more expensive blue color. Having none of this, [Dan] replaced these sad innards with an Arduino Pro Mini which he programmed to drive an old salvaged speaker and three bright RGB LEDs borrowed from the end of a light strip. For the unnecessary but cool part, he used the additional pins of the Arduino micro-controller to add four touch sensitive buttons on the outside of the pink casing. These small capacitive tiles made from copper tape activate sound and change the color of the LEDs when touched, making the pillow a lot more reactive than it was before.

The Arduino Mini board and the added components fit nicely inside the original pink casing of the pillow when all was soldered up and finished. With threefold ultra bright LEDs and a super strobe mode, his daughter’s Hello Kitty pillow is more of a disco ball than a night light now… but we doubt she will complain about the cool additions. To see the pillow in action and hear more about the upgrades you can check out [Dan's] video below:

Filed under: Arduino Hacks, toy hacks

The Trompe-l’œil Menorah

ศุกร์, 11/21/2014 - 04:00

Hanukkah decorations have been up in stores since before Halloween, and that means it’s time for electronic Menorahs with blinking LEDs, controllers, and if you’re really good, a real-time clock with support for the Jewish calendar. [Windell] over at Evil Mad Scientist just outdid himself with the Mega Menorah 9000. It’s a flat PCB with nine LEDs, but it uses stippling and a trompe-l’œil effect to make it appear three-dimensional.

Making a 2D object look three-dimensional isn’t that hard – you just need the right shading. A few years ago, [Evil Mad Scientist] created StippleGen, a library to turn images into something that can be easily reproduced with the EggBot CNC plotter. It’s actually quite impressive; there are Voronoi diagrams and travelling salesmen problems, all to draw on eggs. The library can be used for much more, like properly shading a PCB so that it looks three-dimensional.

The Mega Menorah 9000 is surprisingly large, at about 7.5″ wide. It’s powered by an ATtiny85 loaded up with the Adafruit Trinket firmware, making it a truly USB enabled Menorah. While it may just be a soldering kit, it is a fantastic looking PCB, something we’d like to see some more examples of in the future.

Filed under: Holiday Hacks

A USB-Controlled POV Light Stick

ศุกร์, 11/21/2014 - 01:00

Wanting to showcase their USB LED strip controller, the folks at Maniacal Labs built a POV LED stick this weekend. Yes, it’s pretty much the same as any other POV LED display you’ve seen; set a camera for a long exposure, wave the POV light stick around, and get a cool pixely image in mid-air. This build is a little different, though: it’s controlled over WiFi with a Raspberry Pi connected to a WiFi network.

The USB LED strip controller in question is the AllPixel, a small board that controls NeoPixels, WS2801, LDP8806, and a bunch of other LED strip controllers over USB. The Stick used for this project consisted of two meters of LPD8806 LEDs, giving 96 pixels of horizontal resolution. A big battery and Raspberry Pi rounds out the rest of the electronics.

Building a LED POV display isn’t that much different from building a LED matrix display; all you have to do is break up the image into individual columns and display them sequentially. To do this, the Maniacal Labs folks whipped up a LEDPOV class that does just that. To get the images, just open the shutter on a camera, wave the stick around, and if you get it right, you’ll have a great pixely image of nyan cat or the rainbow wrencher.

Filed under: Crowd Funding, led hacks

Bluetooth Boombox for that 80s Nostalgia

พฤ, 11/20/2014 - 22:00

Sure, anyone can go buy a bluetooth speaker for their portable music needs. But for something a little more unique, at least in this decade, [Daniel] aka [speedfox] went with an 80s-style boombox and outfitted it with a bluetooth module.

The retro boombox was delivered with a few scratches and a broken radio, but the tape decks were still in decent shape so it was ready to be hacked. [speedfox] tied the Bluetooth audio output to the tape reader on one of the boombox’s tape decks, but this revealed a problem: the bass was overwhelming the rest of the sound. [speedfox] fixed this by adding a filter which worked until the power was tied in to the Bluetooth module and produced a lot of RF noise in the audio output. THIS problem was finally resolved with an audio transformer on both sides of the stereo signal. Finally!

After putting all of the new electronics in the case (and safely out of the way of the 120V AC input!) [speedfox] now has a classy stereo that’s ready to rock some Run-D.M.C. or Heavy D. He notes that the audio filter could use a little tweaking, and he’d also like to restore the functionality of the original buttons on the boombox, but it’s a great start with more functionality than he’d get from something off-the-shelf!

Filed under: musical hacks

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