It fails the "only" criterion (it costs more than $2.20, whereas the author had a strict $1 cut-off precisely stating that a huge field opens up above that price range.)
Fom "the rules":
>While some projects that come across my desk are complex enough to require a hundreds-of-MHz microcontroller with all the bells and whistles, it’s amazing how many projects work great using nothing more than a $1 chip — so this is the only rule I established for the shoot-out.
>I wanted to explore the $1 pricing zone specifically because it’s the least amount of money you can spend on an MCU that’s still general-purpose enough to be widely useful in a diverse array of projects.
>Any cheaper, and you end up with 6- or 8-pin parts with only a few dozen bytes of RAM, no ADC, nor any peripherals other than a single timer and some GPIO.
>Any more expensive, and the field completely opens up to an overwhelming number of parts — all with heavily-specialized peripherals and connectivity options.
Of course, the ESP8266 is precisely this "hundreds of megahertz" chip (160 Mhz) with "heavily specialized connectivity options" and peripherals (wifi and, in the case of ESP8265, a full megabyte of flash memory). While all this is interesting, at the $2+ price there are "an overwhelming number of parts."
