Microcontrollers

One of the driving factors of innovation in the field of embedded systems is cost, since they will often be high-volume, cheap consumer products. To that end, it helps to have the entire microprocessor, memory, storage, and input/output peripherals on a single chip, simplifying implementation effort, reducing PCB real estate, all with the added benefit of faster and simpler design and production with higher yield. This led to the development of microcontrollers (MCUs) during the 1970s: single-chip computer systems that could be added to a new design for a minimal cost.

With the introduction of Electrically Erasable Programmable Read-Only Memory (EEPROM) to MCUs in the early 1990s, it first became possible to rewrite the program memory of MCUs repeatedly without having to resort to erasing memory content using ultraviolet light through a special quartz window in the MCU's packaging. This allowed for much easier prototyping and further reduced cost and - as far as development and lower-volume production is concerned - in-circuit programming.

As a result of this, many systems that were previously controlled by intricate mechanical and analog mechanisms (like elevators and temperature controllers) now contain one or more MCUs, which handle the same functionality while reducing costs and increasing reliability. By having the features handled in software, developers were also free to add advanced features such as complex preset programs (for washing machines, microwaves, and so on) and simple to complex displays to provide feedback to the user.