Microcontroller programming is one of the most critical and least visible areas of current technological development. It is at the core of virtually all modern electronic devices, from industrial systems and medical equipment to environmental sensors, consumer products and IoT solutions.

It is through this software component that hardware gains behaviour, decision autonomy and the ability to interact with the real world.

For companies that develop electronic products or interconnected systems, microcontroller programming is often the starting point to transform an idea into a functional, reliable and production-ready product.

What is a microcontroller and how is it different from a processor

A microcontroller is a small computer integrated into a single chip, designed to execute specific tasks in embedded systems. Unlike conventional processors used in computers, which are designed for general-purpose performance, microcontrollers are built for well-defined tasks, with high energy efficiency and deterministic behaviour.

A single integrated circuit includes the processing core, RAM, flash memory and a set of peripherals that allow the chip to interact with the external environment, control devices and execute embedded logic.

Programming a microcontroller means creating the firmware that defines how it operates. From collecting data from sensors to controlling motors or managing power consumption, it is the code that defines each action and reaction of the device.

The practical process of programming a microcontroller

Programming a microcontroller involves much more than simply writing lines of code. It is a technical process that requires deep knowledge of the chip architecture, project requirements and the interaction between software and hardware.

Everything begins with choosing the appropriate microcontroller, considering factors such as memory, communication interfaces, energy consumption and environmental conditions. This is followed by configuring internal resources, writing the main code, performing functional tests and applying specific optimisations.

During development, responses to external events are defined, as well as the operating modes of the system, fault detection mechanisms, power management strategies and communication handling. In more demanding projects, the firmware may also include remote updates, automatic diagnostics or collection of operational metrics.

This type of development requires rigour, execution time control and precision in managing limited resources, as any failure can compromise system reliability.

Languages, tools and common approaches

The C language remains the most widely used in microcontroller programming, especially due to its proximity to hardware, its control over memory and the efficiency of the generated code. In some projects, C++ is used for additional modularity, or Rust for increased memory safety.

Tools vary depending on the manufacturer. For STMicroelectronics microcontrollers, STM32CubeIDE is commonly used. Microchip provides MPLAB X, and manufacturers like Espressif, NXP and Texas Instruments offer their own development environments and libraries.

At Detus, we use the tools most appropriate for each case, based on the project’s requirements and the reliability expected in production. The choice of tools and libraries is not merely technical. It directly impacts the durability, maintainability and performance of the final product.

Generic tools such as GCC (GNU Compiler Collection) and development environments based on Makefiles, CMake or VS Code are also frequently used, especially in projects that require greater flexibility or portability across platforms.

During the MVP phase, we prefer to use development kits specific to the target microcontroller that will be used in the final product. This approach allows us to validate concepts quickly without compromising the firmware architecture or introducing unnecessary abstraction layers. This avoids the need for later porting and ensures that we work from the start with the same tools, peripherals and constraints that will be present in production.

Technical challenges in firmware development

Firmware development for microcontrollers presents several challenges not found in traditional software. First, resources are limited. RAM and program memory are reduced, requiring developers to manage each variable, buffer or structure carefully, precisely and responsibly.

Another challenge is timing control. Many devices react to physical events in real time, which requires efficient management of interrupts, timers and execution cycles. A small failure in execution order can compromise functionality, response and the expected logic of the system.

The physical environment is also a relevant factor. Many devices operate under extreme temperatures, with electromagnetic noise, power fluctuations and prolonged operating cycles. That is why functional, thermal and endurance tests are essential.

Security is also an increasingly important concern. Firmware must be resistant to tampering, protect sensitive data and allow secure updates, especially when the device is connected to the internet.

Integration with external systems and connectivity

Nowadays, programming a microcontroller rarely ends with the device itself. In most cases, communication with gateways, remote servers, mobile applications or management platforms is required. This communication can be carried out via interfaces such as UART, I2C, SPI or CAN, or through more advanced protocols such as MQTT, HTTP or CoAP.

At Detus, we develop firmware that integrates easily with external systems, while meeting security, interoperability and performance standards. We believe that integration between firmware, hardware and management software must be fluid, reliable and predictable, even in adverse conditions.

This approach allows us to create products that not only collect data, but also adapt to their context and communicate with the organisation’s entire digital ecosystem.

Why custom development is essential

Each project has unique technical, environmental and functional requirements. A low-power sensor for agriculture is not comparable to a medical device with strict regulatory requirements, nor to an industrial system operating 24 hours a day.

That is why, at Detus, we develop custom firmware, aligned with the hardware that we also design in-house. This approach enables us to deliver complete solutions, with better performance, greater reliability and precise integration between software and electronics.

By eliminating the fragmentation between hardware design and code development, we reduce failures, accelerate the development timeline and ensure everything works as expected from day one.

Our experience ranges from simple projects with digital sensors to complex architectures with multiple communication channels, proprietary protocols and cloud integration.

Conclusion

Microcontroller programming is an essential skill in the development of modern technology. It is through this firmware that devices come to life, respond to their environment and communicate with the outside world.

In a scenario where innovation increasingly depends on smart, compact and interconnected products, firmware becomes a strategic component. It requires technical knowledge, attention to detail and an approach focused on reliability and results.

If you are looking to develop an electronic product, a connected solution or an embedded system with demanding requirements, Detus can help. We develop hardware and firmware tailored to your challenge, from concept to the delivery of a functional prototype, through to a final, tested and production-ready product.

Schedule a call with us and take the next step in developing your product.