Retrotechtacular: ⋅⋅⋅⋅ ––– ⋅–– – ––– –– ––– ⋅–⋅ ⋅⋅⋅ ⋅ –⋅–⋅ ––– –⋅⋅ ⋅

February 3, 2015 by Kristina Panos 12 Comments

There’s a lot to learn from this 1966 Army training film about the International Morse Code, but the most crucial component of good keying is rhythm. A young man named [Owens] demonstrates very clean keying, and the instructor points out that skill is the product of sending uniform and short dits, uniform and short dahs, and correct spacing between dits, dahs, letters, and words.

Throughout the film, there are title cards in a typeface that shows the stroke order of military printing. The instructor points this out after a brief interlude about the phonetic alphabet (Alpha, Bravo, Charlie, &c). Right away, we see that the Morse Code for ‘H’ is four dits that gallop with the rhythm of a horse in a hurry to get to the hotel.

Such clever and memorable pictures are painted for a few other letters. We wish he would have covered them all, but that’s not the aim of this film. The Army is more concerned with good, clean rhythm and proper spacing that marks the difference between ‘low’ planes and ‘enemy’ planes. There’s a simple, three-step plan to getting what is called a ‘good fist’, and the Army demonstrates this in the best possible way: a giant J-38 and fake hand descending from the ceiling to match. Yes, really.

The first step is to adjust the key to ensure good contact alignment, proper gap spacing, and ideal spring tension. The second step is to develop good technique by resting one’s elbow on the table and holding the key rather than slapping it. The third step is simply to practice. Learning through imitation is helpful, as is taping one’s practice sessions and playing them back. [Owens] likes to use an RD-60 code recorder, which immortalizes his signals in ink.

Continue reading “Retrotechtacular: ⋅⋅⋅⋅ ––– ⋅–– – ––– –– ––– ⋅–⋅ ⋅⋅⋅ ⋅ –⋅–⋅ ––– –⋅⋅ ⋅” →

The Teensy LC. LC Means Low Cost.

February 3, 2015 by Brian Benchoff 50 Comments

For one reason or another, we’ve been seeing a lot of builds featuring the Teensy 3.1 filtering in on the tip line recently. In retrospect, it’s somewhat obvious; it’s a good board that’s cheap and fast. Yes, somehow [Paul] hit all three in the good/cheap/fast mutually exclusive triumvirate.

Now, there’s a new Teensy. It’s the Teensy LC – Low Cost. It’s not as powerful as the Teensy 3.1, but it does give you the power of an ARM for something that’s just about as cheap as a board with an ATMega.

The chip [Paul] chose for the Teensy LC is the Freescale MKL26Z64 (datasheet here and 876-page reference manual here. PDFs of course). This is a 32-bit Cortex-M0+ running at 48 MHz with 64k of Flash and 8k of RAM. There are 27 digital I/O pins on this one, and the Teensy LC has been designed to be pin-compatible with the Teensy 3.0 and 3.1.

On board are 13 analog inputs, 8 PWM outputs, on 12-bit DAC output, three serial ports, two SPI ports, and two I2C ports. Most of the pins can drive 5mA with a few capable of driving 20mA, and there is a single 5v output pin for driving WS2812 Neopixel LEDs.

Since this is a cut-down version of the Teensy, everything available on the Teensy 3.1 just can’t fit into the BOM of the Teensy LC. The pins aren’t 5V tolerant, there’s no CAN bus, and there are only 4 DMA channels instead of 16 on the Teensy 3.1. Still, it’s a great ARM answer to the ATMega Trinket or other small dev boards.

Self-Charging Jacket Eliminates Forgetfulness

February 3, 2015 by Bryan Cockfield 23 Comments

Certain parts of the Northern Hemisphere are very, very cold right now. For those of us living in these colder climates, [Aaron] has a simple yet effective hack for keeping your hands warm when you go out for a walk in the brisk cold. He’s wired his jacket up for USB charging so he can make sure his hand warmers are always working.

[Aaron] bought a set of handwarmers that conveniently charge over USB, but he always forgot to actually plug them in once he got home, ensuring that they were always dead. To make his forgetfulness a non-issue, he built the USB charger for the handwarmers into his jacket, but he didn’t just run a wire out of the pocket. The USB charging circuit runs through the coat hanger, using some conductive cloth and steel thread in the inside of the jacket’s shoulders. From there, the cloth makes contact with the metal arms of the hanger and runs out of the hanger to the wall outlet.

This is a great cold-weather hack that might help any forgetful people on the north side of the planet keep warm. You could even use this method to charge batteries used in other wearable electronics. This project is a great reminder that sometimes the best hacks are the simple ones that no one’s thought of yet!

Caption CERN Contest

February 3, 2015 by Adam Fabio 17 Comments

To say Hackaday has passionate folks in our comments section would be an understatement. You’ve made us laugh, made us cry, and made us search high and low for the edit button. From the insightful to the humorous, Hackaday’s comments have it all. So, we’re putting you to work helping out an organization that has done incredible work for science over the years.

The European Organization for Nuclear Research (CERN) has quite a storied 60 year history. CERN has been involved in pursuits as varied as the discovery of neutral currents, to Higgs boson research, to the creation of the World Wide Web. Like any research scientists, CERN staff have always been good about documenting their work. Many of these records are in the form of photographs: hundreds of thousands of them. The problem is that no one kept records as to what each photograph depicts!

The folks at CERN are trying to remedy this by publishing over 120,000 unknown photos taken between 1955 and 1985. The hope is that someone out there recognizes the people and equipment in the photos, and can provide some insight as to what exactly we’re looking at.

Here at Hackaday we think these photos should be seen and discussed, and we’re going to have some fun doing it. To that end, we’re hosting the Caption CERN Contest on Hackaday.io. Each week we’ll add a project log with a new image from CERN’s archives. If you know what the image is, click on CERN’s discussion link for the photo and let them know! If you don’t know, take a shot at a humorous caption. Hackaday staff will pick the best caption each week. Winners will get a shirt from The Hackaday Store.

Here’s how it will work: A new project log will go up every week on Tuesday night at around 9pm PDT. The project log will contain an image from CERN’s archives. You have until the following Tuesday at 9pm PDT to come up with a caption, and drop it in the comments. One entry per user: if you post multiple entries, we’ll only consider the last one.

The first image is up, so head over and start writing those captions!

Good Luck!

How Fast Is Your Flash?

February 2, 2015 by Brian Benchoff 15 Comments

What’s cooler than learning about timers and interrupts on AVRs? Well, if you’re like [Matt], you can use that learning experience to build something useful – in this case, a timer for various camera flashes.

There are two ways to measure the speed of a flash. The first is the lag between when a button is pressed and when the flash goes off. As long as this is consistent, everything’s okay. The second type of speed is the pulse width. When looking at a xenon flash as time vs. brightness, they have a large spike at the beginning followed by a significant amount of decay. LED flashes are pretty much one cycle of a square wave.

To measure both types of flash speed, [Matt] used a $0.50 photodiode an a 3.5mm jack that ties into the flash remote. These bits are wired up to an Arduino, a little bit of fun work with timers and interrupts happens, and [Matt] learns how fast his flash is.

Suburu Dash Mounted Nexus 7 Looks Like Stock

February 2, 2015 by James Hobson 40 Comments

Nexus 7 tablets, being cheap and really quite decent for the price, have long since been used in the dashboards of people’s cars. Sometimes they’re mounted quite good — sometimes not so good — but every once in a while, someone gets it right.

Usually the reason mods like this don’t work out so well is because people are worried about damaging their car’s interior. But [tsubie320] had a better idea — buy a radio bezel off eBay to mess around with — that way he can always revert to stock when he sells the vehicle.

With a crisp-new-freshly-injection-molded-bezel in hand, he got to work. Funny enough, Nexus 7’s tend to be almost the exact size of double DIN stereo slots — hence their appeal. He wrapped the tablet in blue painter’s tape and positioned it in the bezel. Using fiberglass, he created a new shell for the tablet to sit inside of the bezel. Lots of sandpaper later and a whole bunch of bondo, he was done. Continue reading “Suburu Dash Mounted Nexus 7 Looks Like Stock” →

Tubes On A Chip

February 2, 2015 by Brian Benchoff 73 Comments

The tubes you’ll find in guitar amps and high-end stereos were first designed in the 30s and 40s, and when you get to really, really advanced tube technology you’d be looking at extremely small tubes made in the 70s for military applications. For 40 years, there really haven’t been many advances in tube technology. Now, at last, there’s something new.

The Nutube 6P1, as this curious invention is called, is a full triode or half of a 12ax7 you’ll find in just about every tube amp ever. Unlike the 12ax7, it consumes 2% of the power required of a normal tube, is 30% of the size of the normal tube, and lasts for 30,000 hours.

This new tube-chip thing was brought to life by Korg, makers of fine musical equipment and Noritake Co., manufacturers of vacuum fluorescent displays. There’s no word on what these tubes will be used in and there’s no data sheet. There will be further announcements this year, so don your speculation spectacles and head to the comments.