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Comment by danso | Hacker News Reader

Of all the "this is how we coded things", debugging stories are my favorite, and are probably the things I re-read most...especially since most of them seem to happen in low-level areas, which I don't get to deal with on a regular basis but still find the intuition and principles to be transferrable.

That said, every time I read one of these...I'm always reminded of a legendary bug report...or at least an old one, because I thought I remember reading it in a Usenet newsgroup posting...it involved some malfunctioning hardware and the cause was related to the floor panels and the proximity of people walking around...and I can't find it to store in my bookmarks. Someone here must know what I'm referring to yet can't summon on Google

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I think this might be it: http://patrickthomson.tumblr.com/post/2499755681/the-best-de...

I believe that's the one...wow, my memory is horrible. You can't get much further from "Usenet newsgroup" than "on a Tumblr". I guess that the story as told took place so long in the past, my brain associated it with the days of reading from a text-browser.

I remember reading that story. IIRC, the bug was was that long running jobs would fail. They eventually traced it to electrical interference generated by a loose floor panel that would move when the user paced over it. Also can't find the link though :(

A friend of mine who works in the embedded space recently had a very similar bug. The component would crash when he stood up from his chair. Apparently the hardware connections were so sensitive that tiny bursts of static electricity through the air were enough to disrupt the whole setup.

If you put an LED, resistor, and MOSFET in series and then attach the gate to a wire, you can often switch the LED on and off by waving your hand around the wire. If you have an oscilloscope, hook it up to the resistor and see if you can find a position of your hand that will switch the transistor at 60hz :-)

This is quite common when working on unshielded electronics. Standing up from a chair, depending on clothes and chair fabric, generates a huge amount of static. Even just walking past can be enough.

Proper hardware development labs have antistatic carpet etc., but in embedded software development, one often doesn't have this luxury and has to be aware.

Static electricity can generate hard X-rays http://www.nytimes.com/2008/10/28/science/28xray.html?_r=0 (in a vacuum at least).

http://www.youtube.com/watch?v=87jnCABBaeY

Overly enthusiastic video demonstrating the issue for those who are curious. :)

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