Beyond Measure: Instrumentation Essentials

The physical world is analog and if we want to interface with it using a digital device there are conversions that need to be made. To do this we use an Analog to Digital Converter (ADC) for translating real world analog quantities into digital values. But we can’t just dump any analog signal into the input of an ADC, we need this analog signal to be a measurable voltage that’s clean and conditioned. Meaning we’ve removed all the noise and converted the measured value into a usable voltage.

Things That Just Work.

This is not new information, least of all to Hackaday readers. The important bit is that we rely on these systems daily and they need to work as advertised. A simple example are the headlights in my car that I turned on the first night I got in it 5 years ago and haven’t turned off since. This is not a daytime running lights system, the controller turns the lights on when it’s dark and leaves them off during the day. This application falls into the category of things that go largely unnoticed because simply put: They. Work. Every. Time. It’s not a jaw dropping example but it’s a well implemented use of an analog to digital conversion that’s practical and reliable.

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Figure 1

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Stolen Tech: The Soviet Superfortress

Boeing’s B-17 was the most numerous heavy bomber of World War II, and its reputation of being nigh indestructible in the face of Messerschmidts and flak cannons is stuff of legend. The first flight of the B-17 was in 1935, and a decade later at the close of World War II, the B-17 would begin to show its age. It could only carry 6,000 pounds of ordnance; the first atomic bombs, Little Boy and Fat Man, weighed 9,700 pounds and 10,300 pounds, respectively. The Avro Lancaster notwithstanding, a new aircraft would be needed for the Allied invasion of Japan. This aircraft would be the Boeing B-29 Superfortress.

On paper, the B-29 nearly holds its own against all but the most modern bombers of aviation history. Yes, the B-29 is slow, but that’s only because jet engines were in their infancy in 1944. This bomber was a forgotten super weapon of World War II, and everyone – Japan, German, Great Britain and the USSR – wanted their own. Only the Soviets would go as far to build their own B-29, reverse engineering the technology from crashed and ditched American bombers.

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The Dark Arts: SQL Injection And Secure Passwords

As the year of 2005 was drawing to a close, a website known as Myspace was basking in popularity. With millions of users, the site was the most popular social networking site in the world. It was unique in that it let users use HTML code to customize their Myspace page. Most of us, c’mon…admit it….had a Myspace page. The coding part was fun! But not everything was changeable with code. You could only upload up to 12 images and the Relationship Status drop-down menu only had a few options to choose from. These limitations did not sit well with [Samy Kamkar], a 19 year old hacker out of Los Angeles.

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Source

It didn’t take [Samy] long to figure out how to trick the site to let him upload more images and change his relationship status to a customized “in a hot relationship”. After hoodwinking the Myspace site with some simple hacks, he realized he could do just about anything he wanted to with it. And this is where things get interesting. It took just over a week to develop a script that would force people who visited his page to add him as a friend. But that wasn’t enough. He then programmed the script to copy itself onto the visitor’s page. [Samy] had developed a self-propagating worm.

The script went live as [Samy] went to bed. He woke up the next morning with 200 friends requests. An hour later the number had doubled. [Samy] got worried and sent an anonymous email to the webmaster warning of the worm. It was ignored. By 1:30PM that day, he had over 6,000 friends request. And like any good hacker worth his weight in floppy drives, his sense of humor had him program the script to also add his name to each visitor’s Heroes List. This angered many people, who deleted him from their page, only to get reinfected moments later when they visited another (infected) page.

[Samy’s] script was raging out of control.  As the evening closed in, his friends count had reached 919,664. It would top the 1 million mark just before Myspace took their servers offline to figure out what was going on. Two hours later, the site was back up. [Samy’s] profile page had been deleted.

[Samy] had used a technique known as cross-site scripting (XSS) to pull off his hack. We’ll touch on XSS in a later article. For now, we’re going to stick to the basics – proper passwords and SQL Injection.

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Thanks For The Memories: Touring The Awesome Random Access Of Old

I was buying a new laptop the other day and had to make a choice between 4GB of memory and 8. I can remember how big a deal it was when a TRS-80 went from 4K (that’s .000004 GB, if you are counting) to 48K. Today just about all RAM (at least in PCs) is dynamic–it relies on tiny capacitors to hold a charge. The downside to that is that the RAM is unavailable sometimes while the capacitors get refreshed. The upside is you can inexpensively pack lots of bits into a small area. All of the common memory you plug into a PC motherboard–DDR, DDR2, SDRAM, RDRAM, and so on–are types of dynamic memory.

The other kind of common RAM you see is static. This is more or less an array of flip flops. They don’t require refreshing, but a static RAM cell is much larger than an equivalent bit of dynamic memory, so static memory is much less dense than dynamic. Static RAM lives in your PC, too, as cache memory where speed is important.

For now, at least, these two types of RAM technology dominate the market for fast random access read/write memory. Sure, there are a few new technologies that could gain wider usage. There’s also things like flash memory that are useful, but can’t displace regular RAM because of speed, durability, or complex write cycles. However, computers didn’t always use static and dynamic RAM. In fact, they are relatively newcomers to the scene. What did early computers use for fast read/write storage?

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It’s Time The Software People And Mechanical People Sat Down And Had A Talk.

With the advances in rapid prototyping, there’s been a huge influx of people in the physical realm of hacking. While my overall view of this development is positive, I’ve noticed a schism forming in the community. I’m going to have to call a group out. I think it stems from a fundamental refusal of software folks to change their ways of thinking to some of the real aspects of working in the physical realm, so-to-speak. The problem, I think, comes down to three things: dismissal of cost, favoring modularity over understanding, and a resulting insistence that there’s nothing to learn.

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Wiring Was Arduino Before Arduino

Hernando Barragán is the grandfather of Arduino of whom you’ve never heard. And after years now of being basically silent on the issue of attribution, he’s decided to get some of his grudges off his chest and clear the air around Wiring and Arduino. It’s a long read, and at times a little bitter, but if you’ve been following the development of the Arduino vs Arduino debacle, it’s an important piece in the puzzle.

Wiring, in case you don’t know, is where digitalWrite() and company come from. Maybe even more importantly, Wiring basically incubated the idea of building a microcontroller-based hardware controller platform that was simple enough to program that it could be used by artists. Indeed, it was intended to be the physical counterpart to Processing, a visual programming language for art. We’ve always wondered about the relationship between Wiring and Arduino, and it’s good to hear the Wiring side of the story. (We actually interviewed Barragán earlier this year, and he asked that we hold off until he published his side of things on the web.)

The short version is that Arduino was basically a fork of the Wiring software, re-branded and running on a physical platform that borrowed a lot from the Wiring boards. Whether or not this is legal or even moral is not an issue — Wiring was developed fully open-source, both software and hardware, so it was Massimo Banzi’s to copy as much as anyone else’s. But given that Arduino started off as essentially a re-branded Wiring (with code ported to a trivially different microcontroller), you’d be forgiven for thinking that somewhat more acknowledgement than “derives from Wiring” was appropriate.

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See what we mean?

The story of Arduino, from Barragán’s perspective, is actually a classic tragedy: student comes up with a really big idea, and one of his professors takes credit for it and runs with it.

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Broken Promises Of The Wankel Engine

Through the history of internal combustion engines, there has been plenty of evolution, but few revolutions. Talk of radically different designs always leads to a single name – Wankel. The Wankel rotary engine, most notably used in automobiles by Mazda, has been around since the late 1950’s. The Wankel rotary is an example of a design which makes sense on paper. However, practical problems cause it to underperform in the real world.

Invention and History

felixwankelFelix Wankel’s engine was conceived during a dream. In it, 17-year-old Felix was driving his car to a concert. When he arrived, he bragged to his friends that his car used a new type of engine – half turbine, half reciprocating. “It is my invention!” he told his friends. Upon waking up, Wankel became dedicated to building his engine. Though he never received a formal degree (or a driver’s license), Wankel was a gifted engineer.

Young Wankel’s checkered history includes membership in several anti-semitic groups in the 1920’s. He was also involved with the founding of the Nazi party. His conflicting views on the direction of the party lead to his arrest in 1933. Eventually released through action of Hitler himself, Wankel joined the SS in 1940. The end of the war saw Wankel spending several months in a French prison for his wartime involvement.

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