66% or better

Hackaday Links: January 12, 2014

hackaday-links-chain

[Kyle] teaches photography and after being dismayed at the shuttering of film and darkroom programs at schools the world over decided to create a resource for film photography. There’s a lot of cool stuff on here like mixing up a batch of Rodinal developer with Tylenol, lye, and sodium sulphite, and assessing flea market film cameras. There are more tutorials coming that will include setting up a dark room, developing prints, and playing around with large format cameras.

[hifatpeople] built a binary calculator out of LEGO® bricks or toys. It started off as a series of logic gates built out of LEGO® bricks or toys in the LEGO® Digital Designer. These logic gates were combined into half adders, the half adders combined into full adders, and the full adders combined into a huge plastic calculator. Unfortunately, buying the LEGO® bricks or toys necessary to turn this digital design into a physical model would cost about $1000 using the LEGO® Pick-A-Brick service. Does anyone have a ton of LEGO® Technic® bricks or toys sitting around? We’d love to see this built.

Think you need a PID controller and fancy electronics to do reflow soldering in a toaster oven? Not so, it seems. [Sivan] is just using a meter with a thermocouple, a kitchen timer, and a little bit of patience to reflow solder very easily.

The folks at DreamSourceLabs realized a lot of electronic test equipment – from oscilloscopes and logic analyzers to protocol and RF analyzers were all included a sampling circuit. They designed the DSLogic that puts a sampler and USB plug on one board, with a whole bunch of different tools connected to a pin header. It’s a pretty cool idea for a modular approach to test equipment.

Adafruit just released an iDevice game. It’s a resistor color code game and much more educational than Candy Crush. With a $0.99 coupon for the Adafruit store, it’s effectively free if you’re buying anything at Adafruit anytime soon. Check out the video and the awesome adorable component “muppets”.

Fubarino Contest: Oscilloscope Clock

fubarino-contest-oscilloscope-clock

Before hearing about the Fubarino Contest [Joseph] never considered adding an Easter Egg to one of his own projects. But after seeing so many contest entries we think this is just the kind of fun extra that needs to make its way into every design!

The subject of his entry is an oscilloscope clock which displays our URL instead of the numbers usually found on a clock face. He’s using a SparkFun board to generate the clock — a piece of hardware we saw about 18 months ago hidden inside of a vintage scope. The feature is unlocked only when displaying roman numerals in combination with a special serial command.

Replacing the numerals with the URL isn’t entirely straight-forward. Since an oscilloscope is a vector display [Joseph] actually had to build his own array of start and end coordinates for each character. Luckily he did a fantastic job of documenting this which will allow you to make it say anything you wish.


This is an entry in the Fubarino Contest for a chance at one of the 20 Fubarino SD boards which Microchip has put up as prizes!

An Oscilloscope on your Wrist

osc-watch2

Calculator watches were the Geek cred of the 80’s. Today everyone is getting smart watches. How can the hip Geek stay ahead? [Gabriel Anzziani] to the rescue with his Oscilloscope Watch! [Gabriel] has made a cottage industry with his micro test tools. We’ve featured his Xprotolab and Xminilab on here on Hack a Day more than once. The Oscilloscope Watch basically takes all the features of the Xprotolab and squeezes them down into a wrist watch.

The Oscilloscope Watch includes an oscilloscope, a logic analyzer, an arbitrary waveform generator, and of course it tells time.  The Oscilloscope Watch’s processor is the AVR XMega128.  [Gabriel] has even included a link to the schematics (PDF) on his Kickstarter page. We really like that 3D printed case, and hope [Gabriel] opens up his CAD designs for us to work with.

Like its predecessors, the Oscilloscope watch won’t be replacing your Tektronix scope, or even your Rigol. Much like a Swiss army knife or Leatherman tool, the Oscilloscope Watch packs a bunch of tools into a small package. None of them are as good as a full-sized tool, but in a pinch they will get the job done. If you are wondering where the probes connect. [Gabriel] states on the Kickstarter page that he will design a custom 9 pin .100 connector to BNC adapter to allow the use of standard probes.

The screen is the same series of Sharp Memory LCD’s used in the Pebble watch. [Gabriel] chose to go with the FPC version of the Sharp LCD rather than the zebra connector.  We’ve learned the hard way that those flex circuits snap at the LCD glass after only a few flexes. Hopefully this won’t impact the hackability of the watch.

Connecting an old scope to a computer

Scope

A friend of [Michael]‘s said his company was getting rid of some old lab equipment and asked him if he wanted a very large and very old digital storage oscilloscope. A ‘hell yes’ and we’re sure a few beers later, [Michael] found an old Gould 200 MHz four-channel scope on his bench. Even 20 years after its production it’s still a capable tool, but the serial ports on the back got [Michael] wondering – would it be possible to plot the screen of the scope on his computer?

The scope has three ports on the back – GPIB, miscellaneous I/O, and RS423. The latter of those ports is similar enough to RS232 that a USB to Serial converter just might work, and with the help of a null modem cable and a terminal, [Michael] was able to connect to this ancient scope.

In the manual, [Michael] found a the serial commands for this scope. The most useful of these is a command that prints out the contents of the scope’s trace memory as a series of 1-byte integers. With a short bit of PERL programming, [Michael] can create a PDF plot of whatever is on the scope’s screen. It’s formatted perfectly for Gnuplot, MATLAB, or even Excel.

Awesome work, and especially useful given these old scopes are slowly making their way to a technological boneyard somewhere.

Write an essay, win a Tektronix scope

tektronix_scope_giveaway

Want a new scope for your hacking pleasures? How about one that rings in at $3650? That price tag makes us cringe, which is why we’re working on our 1k word essay to win one. The Tektronix MSO2024B pictured above is the top scope in its family and there’s more than enough features to start the drool flowing. Need more motivation? Check out the demo/advertising video below which walks through an overview of what the scope has to offer.

The contest — sponsored by EETimes and Tektronix — seeks to reward the best story about fixing a product that was disappointing on delivery but awesome when you got done hacking on it. Your thousand words or less are due by October 26th along with a fifty word bio about yourself, with the winner announced on Halloween. Be warned, you must register an account to qualify But we hit their daily article viewing limit while writing this post so you may need to log in just to read about the contest. Or clear their cookies… we are a hacking website after all.

They’re only giving away one scope. So don’t put this one off. Start polishing your totally bogus legit story about how you fixed something using mad engineering skills.

[Read more...]

Bode plots on an oscilloscope

bode

Bode plots – or frequency response graphs – are found in just about every piece of literature for high-end audio equipment. It’s a simple idea, graphing frequency over amplitude, but making one of these graphs at home usually means using a soundcard, an Excel spreadsheet and a multimeter, or some other inelegant solution. Following a neat tutorial from [Dave Jones], [Andrew] came up with a very simple way to make a Bode plot in real-time with an oscilloscope, a microcontroller, and a few off-the-shelf parts.

The basic idea behind [Dave Jones]‘ impromptu Bode plotter is to configure a frequency generator to output a sine wave that ramps up over a period of time. Feed this sine wave through a filter, and you have amplitude on the vertical axis of your ‘scope and frequency on the horizontal axis. Boom, there’s your Bode plot.

[Andrew] did [Dave] one better by creating a small circuit with an Arduino and an AD9850 sine wave generator. Properly programmed, the AD9850 can ramp up the frequency of a sine wave with the Arduino outputting sync pulses every decade or octave of frequency, depending if you want a linear or log Bode plot.

It’s a nifty little tool, and when it comes to building test equipment from stuff that just happens to by lying around, we’ve got to give it up for [Andrew] for his really cool implementation.

 

Playing with an oscilloscope you’ll (probably) never own

We’ll have to admit that we were really jealous when [Shahriar] sent us a video he made, in which he casually explains how a $500,000 160GS/s 62GHz oscilloscope works and then starts playing with it.

Even though you need to be quite familiar with electronics to fully understand the oscilloscope’s inner workings, [Shahriar]‘s step by step explanation is still approachable for those who only understand the basics.

In the first half of the video he uses the manufacturer’s documentation which contains the oscilloscope block diagrams, so you’ll also learn about:

  • timer interleaved Analog to Digital Converters (ADCs), which allows you to increase your input sampling rate by using several of them
  • phase-locked loops, which use a reference clock to generate a much faster clock signal
  • custom made dies and the materials used for high frequency electronic components

In the second half of the video [Shahriar] connects a pseudo random binary sequence generator and uses the oscilloscope to make several measurements that you’d typically want to know for high speed signals (jitters, eye quality factor…). He later performs a small experiment where he up-converts the frequency components of two random 3.12Gbit/s signals and tries to recall each original signal using the oscilloscope functions, making this part of the video a bit harder to keep up with.