Breadboard Friendly FPGAs

December 11, 2012 by Brian Benchoff 57 Comments

Regular Hackaday readers will be familiar with all the cool things you can do with FPGAs; emulating old video game consoles, cracking encryption protocols, and DIY logic analyzers become relatively simple projects with even a modest FPGA dev board on your workbench. Many FPGA boards aren’t geared towards prototyping, though, and breadboard friendly devices are hard to come by. Here’s a pair of breadboardable FPGAs we’ve found while searching for some related hardware over the past few days

First up is the Mercury FPGA Module. Packaged in a DIP-64 format, the Mercury features a Spartan-3A FPGA with the equivalent of 200k logic gates. Elsewhere on the board is 512kB of RAM and 128kB of Flash storage. There are enough GPIO pins for nearly any project, but sadly only a 10-bit ADC – the same resolution you’d find in an AVR or PIC ‘micro.

Of course the Mercury isn’t the only breadboard-friendly FPGA dev board out there. There’s also the slightly more capable XuLA2 board powered by a Spartan-6 with 32 MB of RAM, 1MB of Flash. Unlike the Mercury, the XuLA2 can also fit in one of those ‘half-sized’ solderless breadboards.

Yes, it’s a different form factor than the commonly recommended Papilio One or the DE0. If you can suggest any other ‘beginners’ (i.e. doesn’t cost an arm and a leg) FPGA boards, leave a note in the comments and we’ll summarize them in another post.

Building A Spectrum Analyzer With Parallel Processing

December 8, 2012 by Brian Benchoff 12 Comments

fft

It’s the end of the semester for [Bruce Land]’s microcontroller design class at Cornell, and the projects coming off the workbench this semester look as awesome as any before. For their final project, [Alexander Wang] and [Bill Jo] designed an audio frequency spectrum analyzer using two microcontrollers in a parallel setup.

This spectrum analyzer takes an audio signal from an iPod, phone, or CD player through a 3.5 mm jack and displays the level for dozens of frequency bands much like an audio visualizer in iTunes or a nice car stereo display. To display these frequency bands, the spectrum analyzer first needs to perform a Fast Fourier Transform on the incoming audio signal. While FFT is extremely fast, the calculations are rather hardware intensive; calculating the frequencies and displaying them on a TV would be a bit much even for the ATMega1284 used in the project.

To graph the audio signal on their small display, [Alexander] and [Bill] broke the build up into two parts – one to do the math on the audio, and another to generate the NTSC video signal for the display.

As seen in the video after the break, the spectrum analyzer works wonderfully, and even though it only functions up to 4kHz, it’s more than enough to see what’s going on in most music.

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$250,000 Hard Drive Teardown

December 7, 2012 by Mike Szczys 64 Comments

worlds-most-expensive-hard-drive-teardown

Have you ever seen hard drive platters this big before? Of course you haven’t, the cost of this unit is way beyond your pay grade. But now that it’s decades old we get a chance to post around inside this beast. [Dave Jones] — who we haven’t seen around these parts in far too long — takes a look inside this $250,000 storage device.

In this episode of the EEVblog [Dave] is tearing down a late 1980’s IBM hard drive. This an IBM 3390. It stores either 1.78GB or 3.78GB. These days we’d never use a mechanical drive for that little storage as flash memory is so much cheaper. But this was cutting edge for servers of the day. And that’s why you’d pay a quarter of a million dollars for the thing.

[Dave] does what he’s known for in the video after the break. He energetically pours over every aspect of the hardware discussing function and design choices as he goes.

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The Story Behind Developing The Sifteo From An Engineer’s Perspective

December 5, 2012 by Mike Szczys 12 Comments

how-the-sifteo-was-developed

The video game industry must be one of the most secretive sectors when it comes to developing the electronic hardware used in the gaming consoles. The big guys don’t want to give anything away — to the competition or to the hackers who will try to get around their security measures. But it seems Sifteo doesn’t share those secretive values. We had a great time reading about the bumpy ride for the developers bringing the gaming system from concept to market. [Micah Elizabeth Scott] wrote the guest post for Adafruit Industries. She was brought on as an engineer for the Sifteo project just after the first version of the interactive gaming cube was released. From her narrative it seems like this was the top of the big hill on the roller coaster ride for the company.

What’s seen above is one gaming cube. The system developed in [Beth’s] story puts together multiple cubes for each game. The issue at hand when she joined the company was how to put more power in the hardware and rely less heavily on a computer to which it was tethered. She discusses cost of components versus features offered, how to deliver the games to the system, and all that the team learned from studying successful consoles that came before them like the long line of Nintendo hardware. It’s a fascinating read if you’re interesting in how the sausage is made.

Teaching The Speak & Spell Four (and More) Letter Words

December 3, 2012 by Brian Benchoff 27 Comments

Before it became the darling of circuit benders the world over, the Speak & Spell was a marvel of modern technology. Complete with a microprocessor and voice synthesizer, the Speak & Spell was able to speak a limited vocabulary that [Furrtek] thought should include words such as, “al qaeda”, “necrosis”, and “butt”. The Speak & Spell included an expansion port for cartridges containing a larger vocabulary, and with a huge amount of effort [Furrtek] created his own Speak & Spell carts that allow it to talk like a sailor.

The Speak & Spell ROMs were stored on a very strange memory chip; instead of a parallel or serial interface, the chip reads five nybbles at a time before returning the saved data. At first, [Furrtek] thought he could get an ATtiny microcontroller, but the way this memory chip is set up made it impossible to send and receive data even on a 400kHz I2C bus.

The project eventually found some decent hardware in the form of a CPLD-based cartridge that was more than fast enough to interface with the Speak & Spell. After that, it was only an issue of converting words into something the speech synth can understand with some old Windows 3.1 software and finally burning a ROM.

The end result is a Speak & Spell with a perverse vocabulary and is much, much more interesting than a circuit bent piece of hardware with a few wires crossed. Check out the video after the break.

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Abstracting Transistors Into High-level Design

November 26, 2012 by Brian Benchoff 10 Comments

Although it’s not the best way of understanding computers, most people tend to imagine electronic devices as black boxes filled with magic and blue smoke. Even microcontrollers, the most fundamental means of computation, are treated like little black plastic centipedes with metal legs. In a series of blog posts, [Andrew Gibiansky] is tearing down the walls of obfuscation and illuminating the world of transistors, gates, and FPGAs.

The first blog post goes over the idea of electronic circuits as a waterfall; a positive voltage is a reservoir on a mountain top and ground is sea level. This idea is extended to the lowly transistor acting as an electronic switch, able to turn a circuit on and off.

Continuing on to logic gates, [Andrew] covers the NOT, AND, and OR gates before moving on the flip-flops and SRAM. These can, of course, be modeled in Verilog and VHDL – programming languages that abstract the world of transistors and gates into a much more human-readable form.

[Andrew] is far from done with his series of blog posts, but judging from his work so far it seems to be a great resource for untangling the obtuse concepts of gates and memory into the coherent design of a computer.

Automated Resistor Sorter Puts Them Into Small Plastic Tubes

November 21, 2012 by Brian Benchoff 15 Comments

This one might be an oldie, but it’s certainly a goodie.

Way back in 2005, [David] and [Charles] needed a project for one of their engineering courses. With so many loose resistors scattered over the lab, they decided to build an automated resistor sorter (PDF warning) to separate these resistors and put resistors of the same value together in the same bin.

The electrical and programming portion of this build is relatively simple – just a PIC microcontroller reading the value of a resistor. The mechanical portion of this build is where it really shines. Resistors are sorted when they pass through small plastic tubes mounted to a wooden frame.

There are several levels of these tubes in [David] and [Charles]’ sorter that move back and forth. The process of actually sorting these resistors is a lot like going down a binary tree; at each level, the tube can go right or left with the help of a solenoid moving that level of the frame back or forth.

[David] and [Charles]’ project wasn’t entirely complete by the end of the class; to do so would require 8 levels and 128 different tubes on the bottom layer. Still, it worked as a proof of concept. We just wish there was a video of this machine in action.

Tip ‘o the hat to [Alexander] for finding this one and sending it in.