Basics of Microcontrollers
A microcontroller is a programmable integrated circuit containing a microprocessor, memory, and I/O peripherals for general purpose control in embedded applications.
Typical Peripherals
Timer/Counters
Most microcontrollers contain timer/counter peripherals that increment a counter register on each cycle of an input clock (internally or externally generated). These peripherals are used for numerous purposes including program timing, timing external signals (i.e. encoders or pulse widths), and generating PWM signals.
Analog-to-Digital Converters
Microcontrollers often contain analog-to-digital converters to read in analog voltages. These peripherals convert a voltage on command or periodically into a digital code that is readable by the processor. Some microcontroller ADCs contain an internal reference voltage, however some may require an external reference to operate.