Many years ago, I got a field report of a few systems that were turning themselves off during the night without warning or seemingly a reason. We had some temperature-monitoring software that would automatically shut the system down if it got too hot, and the logs showed that was what was happening. But it was November and the systems were in snowy regions, so too-hot didn't make sense.
A quick look through the code showed me the problem. The programmer was reading the current temperature as an unsigned byte instead of a signed one (as the data sheet for the part specified), so that an actual temperature of -1° C (which is crazy cold for a system) was being read as 255° C, and so it would shut down immediately. Later investigation found that the affected systems were in unheated loading dock areas.
The fix was, of course, easy, but testing it required putting the system in our kitchen freezer (with the various cables coming out for power, the monitor, and so on). The CEO walked in while I was sitting there with a keyboard, mouse, and monitor seemingly hooked up to the refrigerator and just said, "I don't think that I should ask what you're doing."
Submitted December 03, 2014 at 09:12PM by TaedW http://ift.tt/12tQpqY talesfromtechsupport
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