Applications of microcontrollers: From simple circuits in electronics to complex systems

To better understand what a microcontroller is and its strengths and weaknesses, let’s start with the simple.

LED flasher

An example of the simplest circuit is an LED flasher, which consists of:

Operating principle

The MC turns the LED on and off at a frequency specified by the program embedded in it.

Reading data from a sensor (more complex example)

This circuit is more engaging for beginners. It will help them build useful devices for the home, thereby increasing their motivation to learn electronics.

For example, it is possible to make devices for measuring the temperature and humidity of the environment.

The scheme includes:

Operating principle

The MC reads data from sensors at specified time intervals, processes it, and sends it to the indicator.

The prototype can be supplemented with indicators, such as atmospheric pressure, illumination, sound level, and so on. This requires the appropriate sensors and a simple program modification. It’s also possible, for example, to connect an audible or visual alarm for excessive temperature, but only through a relay to ensure sufficient power. This can be accomplished with virtually no expense, simply by modifying the program. Using simple microcontrollers, dozens of device modifications can be implemented without resorting to complex hardware redesign.

These characteristics make the MC a good choice for radio amateurs and students who want to create projects.

This flexibility and versatility of microcontrollers have led to the emergence of modular designs that simplify the development and debugging of circuit prototypes. Among these, the Arduino and Raspberry Pi platforms stand out.

Arduino is a versatile platform suitable for projects that integrate sensors with actuators. Its features include:

Many Arduino simulator programs have also been developed for developing and initially debugging simple bare-metal circuits on a computer or tablet. These include UnoArduSim, as well as cloud-based simulators like Tinkercad and Arduino Create.

Application area:

Raspberry Pi is a mini-computer that can solve complex problems. Its features include:

Application area:

The choice between Arduino and Raspberry Pi is determined by the scale of the project. Both platforms allow for the creation of various circuits, but require different levels of developer experience. To solve combined problems, projects are created using both platforms simultaneously, leveraging the strengths of both. For example, in robotics, the Arduino handles peripheral communications, while the Raspberry Pi serves as the computing center. If you’re just starting, it’s recommended to start with a simpler platform, such as Arduino.

The advantages of microcontrollers in simple circuits have been appreciated.

Let us now consider their advantages in complex systems.

Automation in a smart home

The idea of ​​home automation was conceived by Nikola Tesla in the late 19th century. But it remained just an idea—the technology to implement it was lacking. Attempts at practical implementation were made by the American Emil Mathias in the mid-20th century. But back then, it was too complex and impractical, so it never gained widespread acceptance. Today, the “smart home” is no longer a rarity. We can thank the microcontroller for this—the heart and brain of electronic devices, without which they would not function. Modern microcontrollers make it possible to build flexible and adaptive solutions by analyzing input data from various sensors.

A “smart home” is a microcontroller with sensors and actuators connected to it. Its embedded software can turn on lights based on a signal from an acoustic sensor, shut off a water tap based on a signal from a leak detector, alert a resident to the smell of gas in the apartment via SMS, and perform other actions within the smart home’s capabilities. Thanks to the microcontroller’s ability to process and store data, more precise customization of system operation scenarios is possible.

Robotics

Today, robotics isn’t just about iron androids planned for the exploration of other planets. It’s come to homes in the form of vacuum cleaners, window and floor washers, educational and entertainment robots, and, finally, robot toys. And microcontrollers have played a significant, if not the primary, role in this. In all these robots, microcontrollers control actuators based on sensor signals. Microcontrollers are used to quickly process information from sensors, motors, gyroscopes, and other actuators. Multiple independent input/output ports allow microcontrollers to simultaneously control different modules.

Application in medicine

Yes, both the blue-eyed robot caregiver Garmi from the Munich Institute of Robotics and Machine Intelligence for caring for the elderly and sick, and the brunette Nadine, who smiles sweetly at her patients at the Institute of Media Innovation at Nanyang Technological University in Singapore, are packed with various microcontrollers. The American company Perceptive is creating and is already successfully testing a dental robot… The microcontrollers in such devices ensure precise coordination of movements and analysis of received sensory data. However, medicine needs not only sensational inventions but also primitive devices to assist nurses, lab technicians, and massage therapists. And this miracle of electronic technology—His Majesty the microcontroller—is everywhere.

Application in nuclear power plants

Nuclear power plants (NPPs) are leaders in terms of energy efficiency and the environmental friendliness of the electricity they generate. However, they are also complex and unsafe facilities. To avoid paying a high price for cheap energy, human error in plant operation must be eliminated as much as possible. To this end, NPPs have implemented specialized automated process control systems (APCS), which also rely on microcontrollers. Complex control systems built on microcontrollers ensure high reliability and minimal operator intervention.

Application on unmanned aerial vehicles (UAVs)

The use of unmanned aerial vehicles for scientific research, surveying, and military purposes is now on the rise. Avionics—a complex of onboard electronic devices that includes control units, including flight and navigation controls—represent the core of flying drones. And microcontrollers again! Microcontrollers ensure continuous communication between navigation sensors and flight control systems.

Application in the automotive industry

A modern car won’t move without electronics. Microcontrollers regulate fuel and ignition timing in the engine management system. They monitor ABS and ESP sensor signals to prevent accidents. They display key vehicle parameters and hazard warning lights on the driver’s monitor. Furthermore, microcontrollers analyze data from cameras and radars to quickly respond to changing road conditions.

Finally, microcontrollers play a key role in the control systems of self-driving cars. They process signals from camera, lidar, and radar sensors, allowing the car to determine its location and surroundings. They control driving modes, provide automated braking and maneuvering, and interact with other road users. Modern automotive electronics utilize multiple microcontrollers operating in parallel across different modules.

Complex systems are subject to stringent reliability requirements, including durability, uptime, resistance to external factors, and maintainability. Therefore, when designing complex systems, specialized circuit design techniques and careful selection of components are required. Programming such devices requires precision and an understanding of the logic of data exchange between components. In particular, microcontrollers must be selected not only based on computing power, but also on acceptable ranges of temperatures, vibrations, shock, and ionizing radiation, as well as other parameters based on specific operating conditions. Furthermore, reliability is affected by the quality of the tools and software used during development and manufacturing. For example, a poor-quality programmer can cause a program to be loaded into memory with errors, leading to unpredictable consequences. If a project uses more than one circuit, the interaction between the microcontrollers of different components must be carefully considered.

Since the microcontroller is the most important component of any modern electronic device, circuit design begins with its selection. The effectiveness of the design ultimately depends on how accurately the microcontroller is selected.

Performance

Basic performance parameters:

Storage device (SD)

Basic types:

Periphery

The MC’s peripherals are the interfaces for communicating with external devices. The main ones are:

Consumer demand, technological advances, and manufacturer competition have flooded the market with a wide variety of microcontrollers, varying in bit depth and architecture. Navigating this flood of options will help developers improve design efficiency.

Bit depth

The processor’s bit depth determines the internal memory capacity and performance limits. Depending on the type, serial microcontrollers have bit depths of 4, 8, 16, 32, and 64.

Architecture

The architecture of the microcontroller is determined by the command system and the method of organizing the memory

There are two types of instruction set architecture: RISC and CISC. Learn more about them:

Program and data codes are stored in the memory. Memory is divided into Von Neumann and Harvard types.

Von Neumann architecture. Instructions and data are not separated in memory. This simplifies the design but can create performance bottlenecks when accessing them simultaneously.

Harvard architecture. Commands and data are stored in separate areas. This improves performance through parallel information exchange.

Comparison of architectures

The acronym AVR stands for Advanced Virtual RISC. Its history began in 1996 at Atmel, later acquired by Microchip.

Currently, three subfamilies are popular:

tinyAVR (ATtinyxxx), megaAVR (ATmegaxxx) and XMEGA AVR (ATxmegaxxx)

TinyAVR is used for simple applications

The MegaAVR’s popularity stems from its multitude of built-in peripherals. It’s suitable for complex projects and solutions.

XmegaAVR is more suitable for complex tasks that require large program memory and high processing speed. It is most commonly found in commercial solutions.

ARM is an acronym for Advanced RISC Machines.

ARM does not manufacture chips, but it designs microprocessors and licenses its technology to third parties for chip production.

For example, STMicroelectronics produces the STM32 family of 32-bit microcontrollers based on 32-bit ARM cores. These include the Cortex-M33, Cortex-M7F, Cortex-M4F, Cortex-M3, Cortex-M0+, and Cortex-M0.

These MCs have impressive parameters even for a wide range of applications:

A wide range of products and free software (STM32CubeIDE) have made these microcontrollers popular among both amateurs and professionals.

8, 16,, and 32-bit PIC (peripheral interface controller) microcontrollers from Microchip Technology Inc. consist of 4 large families:

Specifications:

These microcontrollers are distinguished by good continuity across different families. They offer software compatibility (shared development tools: the free MPLAB IDE, shared libraries, and common stacks for the most popular data transfer protocols), pin compatibility, peripheral compatibility, and supply voltage compatibility.

Microcontroller programming involves loading a digital code into the memory. A special electronic device called a programmer is used for this purpose. Programmers are categorized by purpose into hobbyist and professional, universal and specialized. Before purchasing a programmer, it’s important to ensure it supports the desired microcontroller type.

Universal programmers are characterized by a wide range of programmable element types. Therefore, they are more in demand in design bureaus and laboratories. They are also popular among radio amateurs.

This is an effective, reliable and relatively inexpensive universal programmer from the Chinese company Ifix.

Advantages:

RT809F Specifications

In a modern car, electronics have certain specific features, to which manufacturers of electronic components adapt, and subsequently, manufacturers of the corresponding equipment.

The Xhorse VVDI PROG automotive chip programmer from Xhorse, a recognized leader in automotive electronics development, is designed specifically for working with memory chips, processors in engine control units (ECUs), immobilizers, instrument clusters, and write-protected transponder chips.

Advantages:

Functional: