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0 pointsyjftsjthsd-h5y ago0 comments

> You know you're dealing with counterfeits and you know they're unreliable, but you've somehow convinced yourself that despite all the uncovered variance sitting on the table, if you keep poking long enough until the component returns some non-edge-case value, then it "works fine".

Yes? Because it usually does? If you test a bunch of fakes and they tend to be either basically accurate xor really inaccurate, and your project isn't super critical, why not? It's like unit testing; if you trust your tests, then any function which passes is probably fine to use. I wouldn't do it for something mission-critical, but for fun hobby stuff I probably would.

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user59944615y ago

Are these SMT components that have to be soldered for testing? Hardware is not as trivial as software to test and replace.

metaphor5y ago

"usually"..."basically"..."probably"...that's a lot of handwaving. Your usecase is both your prerogative and your folly to embrace; that's not the point.

I poke fun at the OP because his qualifier for "works fine" is an indeterminate definition of eventually establishing some semblance of compliant 1-wire communication with a counterfeit component without even so much as batting an eye to question the accuracy of the sensor measurement being read in, let alone:

  a) environmental constraints
  b) electrical constraints
  c) timing constraints
  d) system integration considerations
  e) counterfeit variance/unpredicability

No, this is not even remotely asymptotic to the implications of software unit testing. This is physical hardware which manifests real variance "vetted" by some half-baked functional "test" that completely ignores every parametric spec without discrimination. Without questioning implementation merits, your software unit tests operate on hash-replicable code...at the silicon level, such a luxury doesn't exist.

yjftsjthsd-hOP5y ago

I think the difference here is that you're taking this from the perspective of an actual engineer, and I'm a hobbyist (and I assumed the same of OP; I hope Real Engineers aren't getting parts off eBay). Which means that, yeah, I'm happy to handwave a lot. By software analogy, I write a lot of shell scripts and python, which is passable but hardly rigorous; if I wanted it to be Correct, I'd break out coq or write in Ada or something, but I just want something that usually works because the stakes are so low. Of course counterfeit parts aren't reliable, but if failure is an option then they're good enough.

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