Why Zephyr?

Posted Apr 9, 2016 18:50 UTC (Sat) by alonz (subscriber, #815)
In reply to: Why Zephyr? by giraffedata
Parent article: Why Zephyr?

These sensors are usually built around single-chip microcontrollers (which often also include all of the digital parts of the sensor itself, so the components external to this chip are mostly passive parts like resistors, capacitors, and the like). Since these microcontrollers use a single piece of silicon to implement both logic and memory, they end up costing very little (often less than $1, in bulk). Unfortunately, dense memories require a different silicon process than processing components (low-power ones in particular), so the memories on such chips take up significantly more space than you would expect per bit of storage.

(As an aside, most dense memories are of the DRAM variety—Dynamic RAM—which requires continuous refresh from the memory controller, and therefore eat through batteries with unholy glee. On Internet-of-Things devices, which are often expected to last for years on a teeny battery, this option is just plain out.)