Friday Hack Chat: ASIC Design

March 15, 2017 by 13 Comments

Join [Matt Martin], ASIC designer at Keysight, for this week’s Hack Chat.

Every week, we find a few interesting people making the things that make the things that make all the things, sit them down in front of a computer, and get them to spill the beans on how modern manufacturing and technology actually happens. This is the Hack Chat, and it’s happening this Friday, March 17, at noon PDT (20:00 UTC).

[Matt] has been working at Agilent / Keysight since 2007 as an ASIC designer. The work starts with code that is synthesized into logic gates. After that, [Matt] takes those gates and puts them into silicon. He’s worked with processes from 0.13um to 28nm. Turning code into silicon is still a dark art around here, and if you’ve ever wanted to know how all of this works, this is your chance to find out.

Here’s How To Take Part:

join-hack-chatOur Hack Chats are live community events on the Hackaday.io Hack Chat group messaging.

Log into Hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Upcoming Hack Chats

We’ve got a lot on the table when it comes to our Hack Chats. On March 24th, we’re going to argue the merits of tube amplifiers in audio applications. In April, we have [Samy Kamkar], hacker extraordinaire, to talk reverse engineering.

Because I’ve never had the opportunity to do so, and because these Hack Chat announcement posts never get many comments anyway, I’m going to throw this one out there. What would it take to build out a silicon fabrication plant based on technology from 1972? I’m talking about a 10-micrometer process here, something that might be able to clone a 6502. Technology is on our side — a laser printer is cheaper than a few square feet of rubylith — and quartz tube heaters and wire bonding machines can be found on the surplus market. Is it possible to build a silicon fab in your garage without going broke? Leave your thoughts in the comments, and then bring them with you to the Hack Chat this Friday.

Surfing Like It’s 1998, The Dreamcast’s Still Got It!

March 15, 2017 by 52 Comments

If you were a keen console gamer at the end of the 1990s, the chances are you lusted after a Sega Dreamcast. Here was a console that promised to be like no other, a compact machine with built-in PowerVR 3D acceleration (heavy stuff back then!), the ability to run Windows CE in some form, and for the first time, built-in Internet connectivity. Games would no longer be plastic cartridges as they had been on previous Sega consoles, instead they would come on a proprietary DVD-like Sega disc format.

It was a shame then that the Dreamcast never really succeeded in capitalizing on its promise. Everyone was talking about the upcoming Sony Playstation 2, and disappointing Dreamcast sales led Sega to withdraw both the console, and themselves from the hardware market entirely.

There remains a hard core of Dreamcast enthusiasts though, and they continue to push the platform forward.The folks at the Dreamcast Junkyard decided to go backwards a little when they resurrected the console’s dial-up modem to see whether a platform from nearly twenty years ago could still cut it in 2017. This isn’t as easy a task as you’d imagine, because, well, who uses dial-up these days? Certainly in the UK where they’re based it’s almost unheard of. They were able to find a pay-as-you go dial-up provider though, and arming themselves with the most recent Dreamkey V3.0 browser disc were able to get online.

As you might expect, the results are hilariously awful for the most part. Modern web sites that rely on CSS fail to render or even indeed to load, but retro sites like those in the Dreamcast community appear as they should. There is a video we’ve put below the break showing the rather tortuous process, though sadly they didn’t think to load the Hackaday Retro Edition. It does however feature the rarely-seen keyboard and mouse accessories.

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How An Oscilloscope Probe Works, And Other Stories

March 15, 2017 by 29 Comments

The oscilloscope is probably the most versatile piece of test equipment you can have on your electronics bench, offering a multitude of possibilities for measuring timing, frequency and voltage as well as subtleties in your circuits revealed by the shape of the waveforms they produce.

On the front of a modern ‘scope is a BNC socket, into which you can feed your signal to be investigated. If however you simply hook up a co-axial BNC lead between source and ‘scope, you’ll immediately notice some problems. Your waveforms will be distorted. In the simplest terms your square waves will no longer be square.

Why is this? Crucial to the operation of an oscilloscope is a very high input impedance, to minimise current draw on the circuit it is investigating. Thus the first thing that you will find behind that BNC socket is a 1 megohm resistor to ground, or at least if not a physical resistor then other circuitry that presents its equivalent. This high resistance does its job of presenting a high impedance to the outside world, but comes with a penalty. Because of its high value, the effects of even a small external capacitance can be enough to create a surprisingly effective low or high pass filter, which in turn can distort the waveform you expect on the screen.

The answer to this problem is to be found in your oscilloscope probe. It might seem that the probe is simply a plug with a bit of wire to a rigid point with an earth clip, but in reality it contains a simple yet clever mitigation of the capacitance problem.

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Mechanical Music Maker Throws Stones

March 15, 2017 by 10 Comments

When we think of a xylophone we envision hitting the keys from above with mallets. But this robot instrument launches stones from below to play a tune. [Niel] calls the device a Pinger and it is part of a Rock Band — all instruments using rocks.

Although the original post has “xylophone” in it, this musical instrument is technically a glockenspiel because it uses metal keys instead of wood. Either way, it’s a work of art; the instrument’s creator ([Neil Mendoza]) was participating in Adobe’s Autodesk’s Pier 9 artist-in-residence program when he built it.

The keys were cut using a water jet, a process not easily in reach for most of us. But you could make do with a different process in a pinch. On the face of it, fabrication seems simple, but there’s software to calculate the right size for the keys depending on the material. The cuts need to be precise to yield an in-tune instrument.

The circular part is laser-cut acrylic, acting as a base for each key. Below the plate there is a cylinder positioned in the middle of the bar which keeps the stone from getting away. When the solenoid fires, the stone flies up and strikes the key, creating a ringing tone but also adding to the body of sound with a rattle when it falls back down to the base. The entire thing is driven by MIDI, so it can play a lot of tunes besides the biographical “Here Comes the Sun” (since, apparently, the pebbles are out in the sun). Check that out in the video below.

This couldn’t help but remind us of another solenoid-driven xylophone — whose keys were machined out of aluminum stock. There’s also the multixylophoniomnibus.

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This WAV File Can Confuse Your Fitbit

March 15, 2017 by 30 Comments

As the devices with which we surround ourselves become ever more connected to the rest of the world, a lot more thought is being given to their security with respect to the internet. It’s important to remember though that this is not the only possible attack vector through which they could be compromised. All devices that incorporate sensors or indicators have the potential to be exploited in some way, whether that is as simple as sniffing the data stream expressed through a flashing LED, or a more complex attack.

Researchers at the University of Michigan and the University of South Carolina have demonstrated a successful attack against MEMS accelerometers such as you might find in a smartphone. They are using carefully crafted sound waves, and can replicate at will any output the device should be capable of returning.

MEMS accelerometers have a microscopic sprung weight with protruding plates that form part of a set of capacitors. The displacement of the weight due to acceleration is measured by looking at the difference between the capacitance on either side of the plates.

The team describe their work in the video we’ve put below the break, though frustratingly they don’t go into quite enough detail other than mentioning anti-aliasing. We suspect that they vibrate the weight such that it matches the sampling frequency of the sensor, and constantly registers a reading at a point on its travel they can dial in through the phase of their applied sound. They demonstrate interference with a model car controlled by a smartphone, and spurious steps added to a Fitbit. The whole thing is enough for the New York Times to worry about hacking a phone with sound waves, which is rather a predictable overreaction that is not shared by the researchers themselves.

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Storing Data On A Single Atom

March 14, 2017 by 11 Comments

In the electronics industry, the march of time brings with it a reduction in size. Our electronic devices, while getting faster, better and cheaper, also tend to get smaller. One of the main reasons for this is the storage medium for binary data gets smaller and more efficient. Many can recall the EPROM, which is about the size of your thumb. Today we walk around with SD cards that can hold an order of magnitude more data, which can fit on your thumb’s nail.

Naturally, we must ask ourselves where the limit lies. Just how small can memory storage get? How about a single atom! IBM along with a handful international scientists have managed to store two bits of information on two pairs of holmium atoms. Using a scanning tunneling microscope, they were able to write data to the atoms, which held the data for an extended period of time.

Holmium is a large atom, weighing in at a whopping 67 AMU. It’s a rare earth metal from the lanthanide series on the periodic table. Its electron configuration is such that many of the orbiting electrons are not paired. Recall from our article on the periodic table that paired electrons must have opposite spin, which has the unfortunate consequence of causing the individual magnetic fields to cancel. The fact that holmium has so many unpaired electrons makes it ideal for manipulation.

While you won’t be seeing atom-level memory on the next Raspberry Pi, it’s still neat to see what the future holds.

Thanks to [Itay] for the tip!

Via Gizmodo.

Google Machine Learning Made Simple(r)

March 14, 2017 by 18 Comments

If you’ve looked at machine learning, you may have noticed that a lot of the examples are interesting but hard to follow. That’s why [Jostmey] created Naked Tensor, a bare-minimum example of using TensorFlow. The example is simple, just doing some straight line fits on some data points. One example shows how it is done in series, one in parallel, and another for an 8-million point dataset. All the code is in Python.

If you haven’t run into it yet, TensorFlow is an open source library from Google. To quote from its website:

TensorFlow is an open source software library for numerical computation using data flow graphs. Nodes in the graph represent mathematical operations, while the graph edges represent the multidimensional data arrays (tensors) communicated between them. The flexible architecture allows you to deploy computation to one or more CPUs or GPUs in a desktop, server, or mobile device with a single API. TensorFlow was originally developed by researchers and engineers working on the Google Brain Team within Google’s Machine Intelligence research organization for the purposes of conducting machine learning and deep neural networks research, but the system is general enough to be applicable in a wide variety of other domains as well.

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