Editing Microcontroller (section)

=== Other microcontroller features ===
Microcontrollers usually contain from several to dozens of general purpose input/output pins ([[General-purpose input/output|GPIO]]). GPIO pins are software configurable to either an input or an output state. When GPIO pins are configured to an input state, they are often used to read sensors or external signals. Configured to the output state, GPIO pins can drive external devices such as LEDs or motors, often indirectly, through external power electronics.

Many embedded systems need to read sensors that produce analog signals. However, because they are built to interpret and process digital data, i.e. 1s and 0s, they are not able to do anything with the analog signals that may be sent to it by a device. So, an [[analog-to-digital converter]] (ADC) is used to convert the incoming data into a form that the processor can recognize. A less common feature on some microcontrollers is a [[digital-to-analog converter]] (DAC) that allows the processor to output analog signals or voltage levels.

In addition to the converters, many embedded microprocessors include a variety of timers as well. One of the most common types of timers is the [[programmable interval timer]] (PIT). A PIT may either count down from some value to zero, or up to the capacity of the count register, overflowing to zero. Once it reaches zero, it sends an interrupt to the processor indicating that it has finished counting. This is useful for devices such as thermostats, which periodically test the temperature around them to see if they need to turn the air conditioner on/off, the heater on/off, etc.

A dedicated [[pulse-width modulation]] (PWM) block makes it possible for the CPU to control [[Switched-mode power supply|power converters]], [[Electrical resistance|resistive]] loads, [[Electric motor|motors]], etc., without using many CPU resources in tight timer [[Program loops|loops]].

A [[universal asynchronous receiver/transmitter]] (UART) block makes it possible to receive and transmit data over a serial line with very little load on the CPU. Dedicated on-chip hardware also often includes capabilities to communicate with other devices (chips) in digital formats such as Inter-Integrated Circuit ([[I²C]]), Serial Peripheral Interface ([[Serial Peripheral Interface|SPI]]), Universal Serial Bus ([[USB]]), and [[Ethernet]].<ref>David Harris & Sarah Harris (2012). ''Digital Design and Computer Architecture, Second Edition'', p. 515. Morgan Kaufmann. {{ISBN|0123944244}}.</ref>