In the world of the Internet of Things (IoT) and embedded systems, where the development process is key, choosing the right microcontroller can determine the success or failure of an entire project. There are many solutions available on the market, but two of them consistently attract the attention of engineers, developers, and electronics enthusiasts: STM32 and ESP32.
At first glance, they seem to serve a similar purpose — acting as the core of embedded systems and devices, responsible for data processing and communication with the external world. In practice, however, they represent two distinct approaches to IoT system design and embedded development . STM32 is synonymous with stability, precision, and support for real-time applications. ESP32, on the other hand, excels where fast network integration, cost effectiveness and a rich open-source ecosystem are essential.
In this article, we compare these two platforms not only based on technical specifications and unique features, but more importantly through the lens of practical applications in IoT projects. We’ll explore their strengths and weaknesses, development environments, communication capabilities, community support, and real-world use cases. If you’re wondering which microcontroller is better suited for your project, or whether combining both might be the optimal solution, you’re in the right place.
STM32 is a family of microcontrollers developed by STMicroelectronics. They are based on ARM Cortex-M cores (M0, M3, M4, M7, M33). STM32 is designed for embedded applications where efficient power management, deterministic behavior, and a wide range of peripheral interfaces are critical. According to the 2024 Embedded Developer Survey by Eclipse Foundation and Statista, STM32 is used by 34% of professional embedded developers.
STM32 MCUs offer advanced timers and precise DMA controllers. They include a variety of ADC/DAC modules and support power management features. These microcontrollers also support industrial-grade communication buses such as CAN, USB, Ethernet, and SPI with enhanced features.
In short, while STM32 offers superior real-time performance, deterministic interrupt handling, better suitability for RTOS-based applications, and multiple power saving modes, the ESP32 excels in cost effectiveness, wireless networking capabilities, and system integration.
In IoT projects, communication is not only about the presence of physical interfaces, but also about ease of use, and stability. The ESP32 stands out with fully integrated Wi-Fi and Bluetooth stacks included in its SDK (ESP-IDF). It supports a wide range of command line tools, and supports multiple communication protocols, such as:
This enables the development of complex networked applications with minimal programming effort. Additionally, the ESP32 provides Ethernet support via external PHY and supports over-the-air updates (OTA), which is essential for remote maintenance.
By comparison, STM32 offers greater flexibility in terms of wired communication interfaces. In addition to standard UART, I2C, SPI, and USB, many STM32 models embrace support for industrial protocols such as:
However, implementing higher-level networking protocols like TCP/IP typically requires integrating external stacks (e.g., LwIP, uIP), which adds to development complexity.
In summary, ESP32 is the go-to solution for projects prioritizing wireless communication and rapid development. STM32, with its superior computing power, is a better fit for systems requiring deterministic behavior and robust wired protocols, especially in industrial or real-time environments.
How do differences in RAM, Flash memory, processing power, and power management between STM32 and ESP32 affect their suitability for various IoT applications? These characteristics have a direct impact on application design and potential use cases.
Choosing between STM32 and ESP32 depends on specific project requirements. STM32 excels in precise control, while ESP32 offers high integration and strong performance in multitasking environments.
If you’re interested in the topic of microcontrollers, we encourage you to read the article:
Both STM32 and ESP32 offer robust development environments, but they take different approaches in terms of tooling, integration, and community support.
For STM32, the development ecosystem includes:
For ESP32, developed by Espressif, the ecosystem features:
In conclusion, STM32 provides an industrial-grade, stable toolchain with precise hardware control—ideal for facilitating extensive data logging, deterministic and mission-critical applications. In contrast, ESP32 focuses on flexibility, ease of integration, and rapid development, especially when using open-source tools and wireless features.
The ESP32 comes with many built-in hardware-level security mechanisms. It supports AES, SHA-2, RSA, and ECC encryption, and includes secure boot, which ensures that only verified firmware can be executed. Additionally, it offers flash encryption, which protects the contents of the Flash memory from unauthorized access. Espressif also provides APIs for key management, OTP (One-Time Programmable) functions, and built-in support for secure communication protocols. These features make the ESP32 a strong choice for cloud-based applications and devices requiring remote firmware updates.
The STM32 also offers extensive security capabilities, though these depend on the specific series. In the higher-end families (such as STM32L5, STM32H5, STM32U5), features involve TrustZone®, memory isolation, secure boot, and hardware accelerators for AES, SHA, RSA, and ECC encryption. STMicroelectronics also provides Secure Firmware Install (SFI) and Secure Boot with Root of Trust (SB-SFU). These features are particularly useful in applications involving industrial control systems. However, they may incur higher hardware debugging costs. This is especially relevant when complying with industry security standards such as IEC 62443.
| Criterion |
STM32 |
ESP32 |
|---|---|---|
| Architecture |
ARM Cortex-M (M0/M3/M4/M7/M33) |
Xtensa LX6 / LX7 (dual-core) |
| Wireless Connectivity |
No built-in |
Built-in |
| Real-Time Performance |
Excellent |
Limited |
| Power Efficiency |
Advanced low-power modes, very low current consumption |
Higher active power consumption, moderate sleep modes |
| Memory Resources |
Flexible |
4–16 MB external Flash, 320–520 KB SRAM, optional PSRAM |
| Development & Debugging |
STM32CubeIDE, CubeMX, HAL/LL libraries, extensive documentation |
ESP-IDF, Arduino IDE, PlatformIO, strong open-source community |
| OTA Support |
Requires custom implementation |
Built-in support |
| Unit Cost |
Higher |
Cost-effective |
InTechHouse carried out a system modernization project for an advanced optoelectronic device. The team replaced an outdated microcontroller with a modern 32-bit STM32 chip, which enabled:
Additionally, an OTA (Over-the-Air) update mechanism was implemented, allowing remote firmware updates and enabling maintenance and further development without physical access to the device.
By using STM32 as the system’s core, InTechHouse achieved efficient data management, deterministic operation, and stable time control for precision tasks. Meanwhile, the ESP32, with its dual core processor, was utilized where wireless connectivity was required—for handling cloud communication, TCP/IP and MQTT protocols, and OTA updates.
As a result, the project combined the strengths of both platforms: STM32 for reliability, precision, and energy efficiency, and ESP32 for rapid network integration and flexible feature expansion. This hybrid approach proved effective in a system that required both stable data processing, remote communication, and various other supplementary features with easy maintenance included.
More about this case you can read here:
There is no one-size-fits-all answer to the question: “Which microcontroller is better?” Both STM32 and ESP32 have earned their place in the IoT ecosystem. Not as competitors, but as complementary tools tailored to different project needs. In practice, hybrid approaches are becoming increasingly common, where both chips coexist, each handling tasks best suited to its strengths. This strategy offers greater flexibility and allows system architecture to adapt to evolving requirements while keeping development costs combined.
If you’re looking for a partner who not only understands technology but truly understands your business needs, InTechHouse is the right choice. Our team combines engineering expertise with a practical approach to embedded and IoT system design. Whether you’re building a product from scratch or navigating the development process, we’re here to help. If you’re upgrading existing hardware or need reliable support with software, hardware, or system integration, we’re ready to deliver. We provide tailor-made solutions to match your specific needs. Trust the experts and book a free consultation today.
Which microcontroller is better for rapid prototyping?
ESP32, thanks to its ease of deployment, Arduino compatibility, and wide range of available open-source libraries.
Can STM32 and ESP32 be used together in one project?
Yes, this is a common approach: STM32 serves as the main control unit, while ESP32 functions as the communication module.
What development environments are available for STM32 and ESP32?
Can I use the Arduino IDE with STM32?
Yes, Arduino support is available for selected STM32 models, but its functionality and stability are more limited compared to ESP32.
Which microcontroller is better for beginners?
ESP32 – it offers an easier learning curve thanks to Arduino IDE support, a large number of tutorials, and many ready-to-use open-source projects.
