Microcontrollers and How They Work
A microcontroller is a compact integrated circuit designed to manage specific operations in an embedded system. A typical microcontroller includes a processor, memory, and input/output (I/O) peripherals on a single chip.
Sometimes called embedded controllers or microcontroller units (MCUs), microcontrollers are found in devices such as vehicles, robots, office machines, medical equipment, mobile radio transceivers, vending machines, and home appliances. They are essentially simple tiny personal computers (PCs) designed to control small functions of larger components without the need for a complex front-end operating system (OS).
How do microcontrollers work?
A microcontroller is embedded inside the system to control a single function in the device. It does this by using the central processing unit to interpret data received from I/O peripherals. Temporary information received by the microcontroller is stored in its data memory, where the processor accesses it and uses instructions stored in its program memory to decrypt and apply incoming data. It then uses its I/O peripherals to communicate and perform the appropriate action.
Microcontrollers are used in a wide variety of systems and devices. Devices often use multiple microcontrollers that work together within the device to handle their respective tasks.
For example, a car may have many microcontrollers controlling various independent systems inside, such as anti-lock brakes, traction control, fuel injection, or suspension control. All microcontrollers communicate with each other to inform proper operation. Some may communicate with a more complex central computer in the car, while others may only communicate with other microcontrollers. They use I/O peripherals to send and receive data and process that data to perform specified tasks.
What are the components of a microcontroller?
The core elements of a microcontroller are:
Processor ( CPU ) - The processor can be thought of as the brain of the device. It processes and responds to various instructions directing the functions of the microcontroller. This involves performing basic arithmetic, logic, and I/O operations. It also performs data transfer operations, communicating commands to other components in the larger embedded system.
Memory - The microcontroller's memory is used to store data received by the processor and to respond to instructions it has been programmed to execute. Microcontrollers have two main types of memory:
1. Program memory, which is used to store long-term information about the instructions executed by the CPU. Program memory is non-volatile memory, which means it can hold information over time without requiring power.
2. Data memory, which needs to temporarily store data when executing instructions. Data storage is volatile, which means that the data it holds is temporary and only retained while the device is connected to a power source.
3. I/O Peripherals - Input and output devices are the interface between the processor and the outside world. Input ports receive information and send it to the processor in the form of binary data. The processor receives this data and sends the necessary instructions to output devices that perform tasks external to the microcontroller.
While the processor, memory, and I/O peripherals are the defining elements of a microprocessor, other elements are often included. The term I/O peripheral itself simply refers to the supporting components that interface with the memory and processor. There are many supporting components that can be classified as peripherals. Having some kind of representation of the I/O peripherals is fundamental to a microprocessor because they are the mechanisms that the processor applies.
Other supporting elements of the microcontroller include:
Analog-to-Digital Converter (ADC) -- An ADC is a circuit that converts an analog signal into a digital signal. It allows the processor at the heart of the microcontroller to interface with external analog devices such as sensors.
Digital-to-Analog Converter (DAC) – The DAC performs the inverse function of the ADC and allows the processor at the heart of the microcontroller to route its output signal to external analog components.
System Bus - The system bus is the connection line that connects all the components of the microcontroller together.
Serial Port - A serial port is an example of an I/O port that allows a microcontroller to connect to external components. It has similar functionality to a USB or parallel port, but differs in the way bits are swapped.
microcontroller application
Microcontrollers are used in several industries and applications, including home and business, building automation, manufacturing, robotics, automotive, lighting, smart energy, industrial automation, communications, and Internet of Things ( IoT ) deployments.
A very specific application of microcontrollers is as a digital signal processor. Usually, the input analog signal has some degree of noise. Noise in this context means fuzzy values that cannot be easily converted to standard digital values. A microcontroller can use its ADC and DAC to convert an incoming noisy analog signal into a uniform outgoing digital signal.
The simplest microcontrollers help operate electromechanical systems found in everyday convenience items such as ovens, refrigerators, toasters, mobile devices, key fobs, video game systems, televisions and lawn watering systems. They are also common in office equipment such as copiers, scanners, fax machines, and printers, as well as in smart meters, ATMs, and security systems.
More complex microcontrollers perform critical functions in aircraft, spacecraft, ocean-going vessels, vehicles, medical and life support systems, and robotics. In medical scenarios, microcontrollers can regulate the operation of artificial hearts, kidneys, or other organs. They also aid in the function of prosthetic devices.
