"For the record, I read several stories about the Nest Protect going into permanent alarm, and you know what my hunch is? The same thing I always assume: "Dumb Linux crap." The culprit was probably some shell script that opened /opt/smoked/detect and output 1 to it and then left the file locked so nothing else could touch it or forgot to delete a pid file or whatever. This is what I always assume when I read about Linux integrated devices screwing up, and on the occasions I've actually heard what the cause was I usually end up right."
As I mention in a separate comment, iFixit's teardown identifies the 100Mhz, 128kB RAM MCU which is the Protect's brain. Such a device does not run Linux. Had the author done any research at all, they would have found this.
Instead, they waded into an unfamiliar topic with the knowledge of a novice and the arrogance of an expert - precisely the accusation they level against Nest.
"The Smart device engineer does not begin by disassembling ten smoke alarms to see how they work. They do not begin by reading papers written by fire chiefs and scientists. They do not look at the statistics on fire-related deaths with and without smoke alarms of different eras (although the marketing department director does)"
All this due diligence and much more was done. The author's lazy speculation insults me and my former co-workers.
This blog post gets lots more important stuff wrong. Suffice it to say that today the Protect is very well-rated by consumers and safety professionals.
The IoT field as a whole is a mess, and deserves much of the author's criticism. Nest, specifically, does not.
On the plus side it still works as a dumb disconnected thermostat, so thank you for that (seriously).
There are real disadvantages of existing hardware.
Take a lock, if you have a cilinder because you need a physical key you have an attack point. Add electronics on top and you only expand the attack service. Get rid of the exposed cilinder! Don't make a plane that flaps like a bird.
Another argument. As an electrical engineer most of my graduates where reinventing wheels with FPGAs. That something is hardware does not mean it cannot contain bugs, I assure you. :-)
Electronics itself improves as well. From lifetimes to power consumption. Everybody knows you should replace batteries of smoke alarms, but people don't always care: turn off the alarm and forget to place a new. There are many ways in which safety can be improved: test the working regularly, have notification messages go to the user if it is not, don't rely on battery only, but also connect the grid, make sure that false alarms can be quickly disabled, have campaigns so that everyone has them, make installation easier, etc. I wouldn't be so sure as the writer that Nest has a netto negative effect because they use a microcontroller in the loop.
I don't have any connection with Nest Protect and don't own one, but the fact that the Protect does not use an ionisation sensor (they suck because they suck at detecting fires early, it has nothing to do with the harmless radioactivity) and used a dual-wavelength photoelectric sensor gives them high marks in my book.
All the hardcore smoke detection equipment -- both the aspirating kinds ("VESDA") and the open-space beam/imaging kinds -- use dual-wavelength sensing. I cannot speak to all the "smart"/"connected" aspects of the device but the smoke sensor seems far better than that of every other residential smoke detector, and it would be very nice if other residential smoke detectors ditched the ionisation sensor and went to a dual-wavelength design.