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[return to "Mazda slaps developer with cease-and-desist for DIY smart home integration"]
1. mirkul+Ek[view] [source] 2023-10-23 22:09:39
>>heshie+(OP)
I've worked for a large OEM, dealing with a large Japanese megacorp that is not Mazda for about two years (actually Mazda was one of our customers too, but I didn't get to work with them directly). This does not amaze me anymore.

We spent months agonizing over an interior temperature sensor, which was only used to display the information to the user on a smartphone app. We built both the hardware and software, and it was offered as an add-on at the dealerships. After months of negotiations, after the hardware was already built and the packages assembles, they decided temperature sensors were too inaccurate (+/- 5 degrees F) to use, and that it could present a legal liability. Again, this was nothing else but displaying the information on the app - and the user could then make a decision whether to remote start the car to cool it or heat it (no automatic process took place either).

This was at the height of "unintended accelerator" issue in Toyotas, so everyone was walking on egg shells playing it ultra safe to not invite any more lawsuits.

What surprises me is that this culture of "playing it safe" remained to this day, some 10 years later (but maybe it shouldn't).

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2. mardif+Tp[view] [source] 2023-10-23 22:41:04
>>mirkul+Ek
Woah I'd have guessed that temperature sensors would be more accurate than that! Is it just an issue of cost, or are most affordable temp sensors that inaccurate and I've never realised it? That would explain a lot though!
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3. throwa+Or[view] [source] 2023-10-23 22:53:39
>>mardif+Tp
If you just buy a bare sensor, yes, it's going to be +/-5. They also have a non-linear response which needs to be dealt with as well.

If you are only concerned about a 20 or so degree temperature range it's not an issue, but if you are trying to read over a 100 degree range, you'll want to account for non-linearity as well.

Also, accurate and precise to 10ths of a degree isn't really attainable unless you do fancy math as the sensor will heat each time you read it. The idea is to take multiple readings and average them but unless you are accounting for the heating of the sensor, your numbers will be garbage.

This is for consumer grade sub $50 sensors. Of course you can go fancier but you have to pay for it.

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