Fast ADC Uses Old School Scope Hack For 48 MSPS

July 21, 2015 by Nava Whiteford 41 Comments

[Carlos] needed an ADC with a 50 nanosecond sample period for his laser lab, that’s 20Msps! (20 million samples a second). While in recent years, commodity ADCs reaching into the low GSPS have become available, integrated acquisition systems are still somewhat expensive. So [Carlos] decided to do what every good hacker does, and built his own solution. His project post pretty much just links to a whitepaper he wrote (PDF) so we’ll try and boil it down for you:

In order to simplify development [Carlos] borrowed a technique commonly used in the first era of digital oscilloscopes, Equivalent Sampling Time.

The figure to the right is from the TDS460 manual. While it may seem counter intuitive to those only familiar with modern scopes, the TDS460 achieved a 400MHz bandwidth using a 100MSPS ADC. In order to achieve this the scope acquires a single trace in multiple cycles, each time offsetting the acquisitions as shown and combining the result.

In this way, early digital scope developers could sidestep the limitations of the available ADCs to achieve a higher effective bandwidth. However there is of course one catch: the technique only works for periodic signals.

This was fine for [Carlos] who implemented a technique on a Cypress PSoC 4, which provides analog FPGA-like functionality. By offsetting the ADC trigger he has able to achieve an EST of 48MHz using a ADC sampling at 1MHz. If you want a little help getting into PSOC 4 yourself, check out the guide that [Bil Herd] made.

Neat hack [Carlos] and we hope to hear more about your laser lab in the future.

“Drones” Endanger Airborne Wildfire Fighting

July 21, 2015 by Adam Fabio 96 Comments

There is no denying that personal drones are in the public eye these days. Unfortunately they tend to receive more negative press than positive. This past weekend, there were news reports of a wildfire in California. Efforts to fight the fire were hampered when no less than five drones were spotted flying in the area. Some reports even stated that two of the drones followed the firefighting aircraft as they returned to local airports. This is the fourth time this month firefighting planes have been grounded due to unmanned aircraft in the area. It’s not a new problem either, I’ve subscribed to a google alert on the word “Drone” for over a year now, and it is rare for a week to go by without a hobby drone flying somewhere they shouldn’t.

The waters are muddied by the fact that mass media loves a good drone story. Any pilotless vehicle is now a drone, much to the chagrin of radio control enthusiasts who were flying before the Wright brothers. In this case there were two fields relatively close to the action – Victor Valley R/C Park, about 10 miles away, and the Cajun Pass slope flying field, which overlooks the section of I-15 that burned. There are claims on the various R/C forums and subreddits that it may have been members from either of those groups who were mistaken as drones in the flight path. Realistically though, Victor Valley is too far away. Furthermore, anyone at the Cajun pass flying site would have been fearing for their own safety. Access requires a drive through 3 miles of dirt road just to reach the site. Not a place you’d want to be trapped by a wildfire for sure. Who or whatever was flying that day is apparently lying low for the moment – but the problem persists.

Rules and Regulations

In the USA, the FAA rules are (finally) relatively clear for recreational drone operations. The layman version can be found on the knowbeforeyoufly.org website, which was put together by the Academy of Model Aeronautics (AMA), The Association for Unmanned Vehicle Systems International (AUVSI), and other groups in partnership with the FAA.

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Why Is There Liquid Nitrogen On The Street Corner?

July 21, 2015 by James Hobson 107 Comments

Any NYC hackers may have noticed something a bit odd this summer while taking a walk… Giant tanks of the Liquid Nitrogen have been popping up around the city.

There are hoses that go from the tanks to manholes. They’re releasing the liquid nitrogen somewhere… Are they freezing sewer alligators? Fighting the Teenage Mutant Ninja Turtles? Or perhaps, cooling our phone lines??

Luckily, we now have an answer. Popular Science writer [Rebecca Harrington] got to investigate it as part of her job. As it turns out, the liquid nitrogen is being used to pressurize the cables carrying our precious phone and internet service in NYC. The cables have a protective sheath covering them, but during construction and repairs, the steam build up in some of the sewers can be too much for them — so they use liquid nitrogen expanding into gas to supplement the pressurized cables in order to keep the them dry. As the liquid nitrogen boils away, it expands 175 times which helps keep moisture out of the cables.

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Learn FPGAs In Your Browser

July 21, 2015 by Al Williams 40 Comments

FPGAs aren’t really programmed, they are configured. Most designers use Verilog or VHDL to describe the desired circuit configuration. Developers typically simulate these configurations before committing them to silicon (a good habit, especially if you ever graduate from FPGAs to ASICs where changes are very expensive). That simulation takes a lot of software you have to install and learn, right?

Not necessarily. You can do e-mail, word processing, and PCB layout in your browser. Why not FPGA design? The EDAPlayground website provides two editor views: one for your main “code” and another for the testbench (the simulation driver you use to test your design). You can even open multiple files, if you have a complex design.

Once you’ve entered your Verilog or VHDL (or picked one of many examples) you can run the simulation and see the result right in your browser. No software to install, and–outside of actually learning VHDL or Verilog–not much learning curve.

As [Strauburn], [combinatorylogic], and others commented on our recent post about a VHDL CPU, you can do a lot of learning without ever having your hands on real hardware. The web site gives you access to several different tools (useful if you want to see how your code will behave on different tools) and also many standard verification libraries. There are limited synthesis tools, but honestly, if you want to go to real hardware, you are going to want the vendor tools for the specific FPGA you are using.

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Hackaday Prize Entry: Two Factor Authentication Key

July 20, 2015 by Brian Benchoff 18 Comments

Because people are generally idiots when it comes to choosing passwords — including people who should know better — Google created Google Authenticator. It’s two-factor verification for all your Google logins based on a shared secret key. It’s awesome, and everyone should use it.

Actually typing in that code from a phone app is rather annoying, and [Alistair] has a better solution: an Authenticator USB Key. Instead of opening up the Authenticator app every time he needs an Authenticator code, this USB key will send the code to Google with the press of a single button.

The algorithm behind Google Authenticator is well documented and actually very simple; it’s just a hash of the current number of 30-second periods since the Unix epoch and an 80-bit secret key. With knowledge of the secret key, you can generate Authenticator codes until the end of time. It’s been done with an Arduino before, but [Alistair]’s project makes this an incredibly convenient way to input the codes without touching the keyboard.

The current plan is to use an ATMega328, a real-time clock, and VUSB for generating the Authenticator code and sending it to a computer. Getting the secret key on the device sounds tricky, but [Alistair] has a trick up his sleeve for that: he’s going to use optical sensors and a flashing graphic on a web page to send the key to the device. It’s a bit of a clunky solution, but considering the secret key only needs to be programmed once, it’s not necessarily a bad solution.

With a small button plugged into a USB hub, [Alistair] has the perfect device for anyone annoyed at the prospect at opening up the Authenticator app every few days. It’s not a replacement for the app, it just makes everything easier.

The 2015 Hackaday Prize is sponsored by:

Flyfish FF32 Gets GUI

July 20, 2015 by Will Sweatman 8 Comments

[CWroos] has written an impressive GUI for the Flyfish FF32. The Flyfish is a port expander of sorts, allowing the user access to a large array of I/O , analog inputs, SPI, I2C and a few other connectivity options over a USB connection. There is no driver as it uses a native HID driver in the operating system of the device it’s attached to. It’s not just tethered to a PC either. It works with Raspberry Pi, Beaglebone and several other SBCs.

[CWroos]’s GUI makes it easier than ever to interact with the FF32. It has a script editor allowing you to run and edit scripts on the fly (pun intended). It appears he’s actually written his own basic like language for the scripting, which he goes into great detail on his site. There’s a blinky script example, and few more complex examples that will show you how to read temperature and control a servo.

There is also the ability to control the hardware directly allowing you to set pins, read firmware version, set the USB address and several other options. If you have an FF32 lying around, be sure to check out [CWroos]’s program and let us know how it works for you.

Automatically Designing 3D Printers From E-Waste

July 20, 2015 by Brian Benchoff 12 Comments

No one wants to design consumer electronics that last longer than a few years. This trend is an ecological disaster, with millions of tons of computers, printers, fax machines and cell phones ending up in landfills. In these landfills, all the lead and chemicals used to extract minuscule amounts of gold plating leech into the environment. Turning it all around is monumental, but reusing some of this waste can help make a difference.

[Masterperson] and [Maaphoo] have been working on a way to turn those tons of e-waste into something useful. They’ve come up with a framework for turning e-waste into 3D printers. With a clever application of Python and FreeCAD Macros, this project can generate a model of a 3D printer using motors, shafts, and bearings taken from discarded 2D printers.

Right now a printer can be configured by adding the parts you have on hand to a configuration file, running a Python macro in FreeCAD, and waiting until the macro generates the parts to build a cartesian bot. This macro also spits out the files for the parts that need to be printed, and can interface with Plater to optimize the placement of these printed parts on an existing printer.

It’s a very cool project, but it’s not done yet: the team is looking for help to refine the printer designs and possibly growing more designs than a simple cartesian bot. Anything that is explicitly designed to pick the meat off of 2D printers is a great idea, and turning those into real 3D printers is the cherry on top.