What Is A Microcontroller and How Does It Work?

10th Apr 2023

What Is A Microcontroller and How Does It Work?

Microcontrollers are vastly different from microprocessors and even digital signal processors. They are a design of integrated circuits compact and tailored to govern any particular operation across any system of embedded systems. A microcontroller usually will have memory, a processor, and I/O (input/output) components on one chip.

They are also called microcontroller units or embedded controller units at times. There is a long list of microcontrollers that you will find used across diverse applications, including medical devices, office machines, vehicles, robots, vending machines, mobile radio transceivers, and even home appliances, among many other types of devices. They are miniature and straightforward personal computers (PCs) tailored to enable the control of more minor features of any more significant component, minus any complicated front-end OS (operating system). You may have used or heard of the Arduino or other microcontrollers.

Now you can know how they essentially function. This makes microcontrollers helpful for several hobbyists and professionals working on diverse project types. Their versatility is second to none in this segment. Microcontrollers can be used across diverse functionalities and setups as well. These nifty devices tap several microcontrollers, which may function together to take care of various activities.

For example, a microcontroller or multiple such options may exist within a vehicle. This enables the control of diverse individual setups, such as traction control, ABS, suspension control, or even fuel injection. These microcontrollers interact among themselves to decide the proper steps to take. Some may interact with more complicated and central computers within the vehicle itself, while others may communicate only with other kinds of microcontrollers. They dispatch data and receive the same with the help of their I/O peripherals while processing this information for executing their specific tasks simultaneously. The microcontroller will be integrated into the system to control any particular function within a device. This is accomplished by interpreting the information gathered from the I/O peripherals with the help of a central processor. The temporary data received by the microcontroller is stored within data memory accessed by the processor while also tapping instructions stored in the program memory to understand and apply all incoming information. It also uses these I/O peripherals to communicate and enact suitable actions. These microcontrollers may be called MCUs or embedded controllers across office equipment, vehicles, robots, mobile radio transceivers, medical devices, home appliances, and even vending machines. They are mini PCs or personal computers tailored to control more minor features of more extensive components, minus any complicated front-end OS or operating setup. These dynamic aspects contribute to microcontrollers being coveted pieces of equipment for diverse purposes and across the hobbyist or professional spectrum.

How do microcontrollers function?

Microcontrollers are mostly embedded within a system to control a particular device's function. It achieves this objective by interpreting data from I/O peripherals received via a central processor. Temporary data received by the microcontroller will remain stored in data memory. The processor will access them while using instructions stored in program memory to decipher and apply incoming data. It then deploys the I/O peripherals for the communication and execution of the suitable action. Microcontrollers are leveraged throughout various devices and systems. Several devices tap different microcontrollers functioning in tandem within a machine to take care of all their tasks. Think of it as a car with several microcontrollers that ensure the proper internal control of several individual systems, including traction control, ABS, suspension control, fuel injection systems, and more. All microcontrollers individually communicate with each other to decide on the right action. A few of them may also communicate with a more complicated central computer positioned within the vehicle, while some may only communicate with other microcontrollers. They receive and send information using their I/O peripherals and process valuable data to tackle all designated tasks.

Microcontrollers: Core Components

Here are the core elements of any microcontroller:

  1. CPU: This is the processor and the device's critical heart. It will process and issue responses to several instructions/commands that enable the functioning of the microcontroller.
  2. This will include I/O, logic, and arithmetic-related operations. It also handles data transfer while communicating the commands to other system components.
  3. Memory: It helps store all the data received by the system's processor and uses responses to instructions as per its programming. The microcontroller setup usually comes with two memory types.
  4. The first one is program memory which is the storage of long-term data regarding the instructions borne out by the CPU. Program memory falls in the non-volatile category, meaning it can hold data over time minus the power source requirement. Data memory is another type of memory.
  5. This is necessary for temporarily storing data while the instructions are being implemented. Data memory falls in the volatile category, meaning that the data it holds is temporary and maintained only when the device is linked to a power source.
  6. I/O Peripherals: The output and input devices are the primary interface for the processor about its relationship to the external world or environment. The input ports get data and dispatch the same to the processor as binary data.
  7. The processor will get this data before dispatching all main instructions to the output devices which will take care of other tasks external to the microcontroller.

There are several other components which are also included in microcontrollers. The I/O peripherals definition may encompass various elements that have processor and memory interfaces. Some further supporting details include these:

  1. ADC: This means an Analog Digital Converter, a circuit, thereby enabling the conversion of analogue to digital signals. It allows processors at the microcontroller's centre to interface with external sensors or analogue devices.
  2. DAC: Digital to Analog Converters help take care of the reverse functionalities of the ADC while enabling the processor in the centre to easily communicate all outgoing signals to the components in the external analogue category.
  3. System Bus: It is a connective wire which connects all the components of microcontrollers with aplomb.
  4. Serial Port: It is an instance of I/O ports which enable microcontrollers to link up with external components. It works similarly to a parallel or USB port, although there is a difference in the bit exchange part.

These are some of the core parts of the microcontroller. You should understand them with care before venturing into the main features.

Features of a Microcontroller

The microcontroller processor will differ as per the application in question. The choices hover between 4-bit, 16-bit, and 8-bit processors and go on to 64-bit and 32-bit processors.

Microcontrollers may tap types of volatile memory, including RAM (random access memory) and non-volatile memory types, such as erasable and programmable read-only memory or EPROM, flash memory, and EEPROM (electrically erasable programmable read-only memory).

Microcontrollers usually enable quick usability without extra computing since they are tailored with excellent memory board while ensuring pins for the usual I/O operations. This facilitates direct interfacing with significant components and sensors alike.

Microcontrollers may have architecture based upon the Von Neumann or Harvard architecture while ensuring various data exchange mechanisms between the memory and processor. The latter system keeps the instruction and data bus separate and demarcated, thereby enabling transfers simultaneously.

The former is a system where a single bus is deployed for instructions and data. The processors may be based upon CISC (complex instruction set computing) or RISC (reduced instruction set computing). The former has approximately 80 instructions, while the latter has close and more addressing modules which are 12-24compared prison to 3-5 for RISC.

CISC is easily implementable with better and more efficient memory, and it may witness degradation in performance owing to more clock cycles for implementing the instructions. RISC is more software-focused while ensuring superior performance compared to CISC processors, which focus more on hardware due to more straightforward instructions.

C is a popular programming language for microcontrollers, while other standard options include JavaScript and Python. MCUs usually have output and input points for the execution of functions at a peripheral level.

These functionalities cover LCD controllers, analogue to digital converters, universal synchronous/asynchronous receiver transmitters (USARTs), RTCs (real-time clocks), USB (universal serial bus) connectivity, and UART (universal asynchronous receiver transmitter).

Some sensors accumulate information linked to temperature and humidity among other factors. Some of these features should be understood carefully before using a microcontroller. At the same time, this will also influence your purchase decision in many ways.

Microcontroller Types

There are several kinds of microcontrollers, with the typical varieties including the Intel MCS-51 or the 8051 microcontrollers which were developed way back in 1985. The AVR microcontroller was formed in 1996 by Atmel, and Microchip Technology created the PIC (programmable interface controller).

There are several ARM (Advanced RISC Machines) microcontrollers available too. There are several leading brands which also retail microcontrollers globally. You have to compare these top names and compare them for features and other aspects in terms of their products. Also, knowing which product is right for you is essential.

Applications of Microcontrollers

Microcontrollers are deployed throughout numerous applications and business sectors, which include enterprise and home, manufacturing, building automation, automotive, robotics, intelligent energy, lighting, communications, industrial automation, and IoT (the internet of things). The actual application of any microcontroller uses the same as a processor for digital signals. A specific noise level usually accompanies incoming analogue-type calls. In this scenario, noise translates to ambiguous values, which cannot always be equated to common digital values. The microcontroller may leverage its DAC and ADC to convert noisy analogue signals, incoming to outgoing and even digital signs. Simpler microcontrollers usually enable the operations of electromechanical systems discovered across regular items of convenience, including toasters, refrigerators, ovens, key fobs, mobile devices, video game systems, lawn-watering systems, and televisions. They are also used throughout office equipment including scanners, photocopiers, printers, fax machines, and other machinery like security systems, ATMs, and smart meters. Several microcontrollers take care of vital functions throughout spacecraft, aircraft, ocean-navigating vessels, life-support systems, vehicles, and robots. Microcontrollers may also function in medical environments, regulating the functioning of artificial kidneys, hearts, and other organs. They may also enable the operations of prosthetic devices alongside. This is only an indicator of how versatile these devices are in reality.

Microcontrollers vs microprocessors

There is often some confusion regarding microprocessors and microcontrollers. Overall complexity levels vary, while chip density is another crucial aspect.

Microcontrollers have already imbibed computer-like functionality and they may also operate by themselves with a direct link to actuators and sensors, where microprocessors are tailored to maximize the chip's computer power and abilities with internal bus connections to the hardware components like serial ports and RAM. Microcontrollers are comparatively more affordable and take up lower power than microprocessors. The latter does not come with integrated RAM, ROM (read-only memory), or other components/peripherals on the chip. Instead, this attaches to the same pins in question. A microprocessor may be perceived as the computer system's central core, while a microcontroller may be the central core of any embedded setup. These are the core differences between microprocessors and microcontrollers. You should keep them in mind and avoid confusing the two types of devices.


In conclusion, a microcontroller is a compact and integrated device that includes the microprocessor, memory, and input/output interfaces, all on a single chip. It is designed to control a specific task or function in an embedded system. Executes instructions stored in its memory, allowing memory, will enable it to carry out specific functions. The microprocessor executes these instructions the microprocessor and can range from simple operations such as counting to more complex tasks such as controlling a motor.

Microcontrollers in modern technology have revolutionized our lives, from powering our appliances to enabling advanced automation systems. Microcontrollers are essential in the contemporary world, and their importance will continue to grow. Selecting the right hardware is a critical decision when embarking on an IoT project. It is important to consider factors such as performance, compatibility, and cost-effectiveness to ensure a successful deployment. Evelta, as a trusted marketplace for electronic components, offers a wide range of genuine and original microcontrollers and other hardware options to suit your specific needs.