Many years ago, I was able to snag a win in the regional Science Fair with a project designed to automatically drive a car. In retrospect it was a ludicrously incapable system, but the judges were kind. Computers weren't available to high school students, so my design used hundreds of RTL ICs spread over many vector boards to handle the control requirements. It never really worked well even in the simulated tests I ran, but was a lot of fun to build.

Over forty years on and now Google and others want to populate our roads, the air, and the sea with self-driving vehicles.

Be a......

My wife is need of an intervention.

She's the sort who never slows down. She is always creating some form of art. The house is overflowing with her stained glass creations. Everything is decorated with mosaics or her paintings. Even rocks in the yard are mosaic victims.

But a few years ago she discovered beading, and, well, let's just say those beaders are nuts. Her bead society is full of similarly-minded women (to a first approximation, all women). They can't go for more than a few microseconds without stringing bits of shiny glass or other materials togeth......

With much fanfare Xilinx launched their Zynq line of FPGAs some months ago. Initial versions comprise a pair of hard-IP Cortex-A9 processors surrounded by a sea of programmable logic.

They're sort of like a super-sized version of Microchip's PIC10F32X family, which is an 8 bit microcontroller with a small amount of programmable logic (what they calls a "puddle of gates"). Both companies push a new kind of product: instead of an FPGA that happens to have a microprocessor or two, these parts are complete microcontrollers with some (in Xilinx's case, rat......

[Continued from Another guide to probing (Part 1)]

I didn't have any X1 probes around, so put a 100-pf capacitor on the node to simulate a really crappy probe. Rise time spiked to 5.5 nsec, more than a five times increase, and the signal was delayed by almost a nsec. I suggest immediately combing your lab for X1 probes and donating them to Goodwill. And be very wary of ad hoc connections—like clip leads and soldered-in wires—whose properties you haven't profiled.

But 100 pf is a really crummy probe. I soldered a 30 pf cap on the node to s......

In my previous article, I gave a mostly theoretical overview of the effect probes—like scope and logic analyser probes—have on the nodes being tested. The most important effects stem from the capacitance of the probe tip. To reiterate, the reactance, or resistance to AC, at the tip is:

This reactance loads the node and can alter a device's operation—or worse.

To explore this, I built a circuit on a printed circuit board with ground and power planes, keeping all wires very short. A 50MHz oscillator drives two AND gates. The 74AU......

Over the decades, I have come across a number of quirky resumes, and I wish I have saved them all. One was printed on bright pink paper, an obvious gambit to make it stand out from the rest of the pile. Others were long... really long, sometimes over 100 pages.

One that I did save twenty years ago (the rest is equally priceless) contains this nugget:

Do you think this person got an interview?

A job opening often results in a deluge of resumes. If you've never hired anyone you might think that the evaluator would carefully dig through the stack, wei......

Nomophobia is an insidious ailment. It is a disease that cripples those afflicted. Perhaps you have a friend or relative who suffers from this condition. I'm sure the United States we'll soon have a Huge Federal Program in place to address the issue.

The mostly-incompetent PR zombies of the world send me hundreds of press releases a week, usually with topics tremendously germane to Embedded.com readers like hair treatments and ED cures. Today a gem from SecurEnvoy, another one of those annoying companies with camel-case names, warns that two thirds of us suffer from no......

[Continued from Guide to probing (Part 1)]

Fourier fits
But it gets worse.

In 1822, Joseph Fourier released his Théorie analytique de la chaleur (The Analytic Theory of heat). That seminal work has tormented generations of electrical engineering students (and no doubt others). Discontinuous functions—like square waves—are very resistant to mathematical analysis with calculus unless one does horrible things like use unit step functions. But Fourier showed that one can represent many of these periodic functions as the sum of sine waves o......

Back when the Earth was beginning to cool and the first creatures were crawling from the slime, we were building a very fast system with plenty of discrete logic because the processors of those Paleozoic years couldn't keep up with our data rates. I was probing a pair of signals on a fabulously-expensive oscilloscope, but their relationship made no sense. Eventually I realized that one of the scope probe leads was a full meter longer than the other. This was the first, but certainly not the last, time I cursed light's snail-like pace. And it was the first time I was forced to think abou......

Route 140 in Finksburg, Maryland is heavily patrolled. In areas like that, going over the speed limit would likely lead to a fine.

But some speed limits can't be exceeded, no matter how much one wishes to. The speed of light comes to mind. As does the speed at which a teenager's brain matures.

Then there are multiprocessor limits. Amdahl's Law tells us that the max speedup achievable is:

where f is the percentage of a problem that cannot be parallelized, and n is the number of processors. In a system, where, say, only 50% of the problem......