Choosing the Right Embedded System for Industrial Applications: From Microcontrollers to Industrial PCs

Choosing the Right Embedded System for Industrial Applications: A Spectrum of Solutions

The landscape of embedded systems for industrial applications spans from versatile microcontrollers and single-board computers to highly robust, purpose-built industrial hardware. Platforms like Arduino, ESP32, STM32, and Raspberry Pi offer remarkable flexibility and rapid prototyping capabilities, while dedicated Industrial PCs (IPCs), Programmable Logic Controllers (PLCs), and industrial System-on-Modules (SoMs) provide the ruggedness, reliability, and long-term support often required in demanding environments.

Selecting the optimal platform requires navigating a complex trade-off between cost, performance, development speed, environmental resilience, and long-term maintainability. As an engineer experienced in deploying a wide range of embedded solutions in industrial settings, I offer this guide to help you compare these different classes of systems and make informed decisions based on your project’s specific needs.

Understanding the Demands of the Industrial Environment

Industrial applications impose stringent requirements that differentiate them significantly from consumer or commercial uses:

• Environmental Toughness: Operation across wide temperature ranges (-40°C to +85°C or more), resistance to vibration, shock, dust, and moisture ingress (IP ratings).
• Electrical Resilience: High immunity to electromagnetic interference (EMI) and radio-frequency interference (RFI), stable operation under fluctuating power conditions.
• Operational Reliability: Designed for continuous 24/7 operation with high mean time between failures (MTBF).
• Longevity and Support: Guaranteed long-term availability of components (often 10-15 years) and sustained vendor support.
• Determinism: Predictable real-time performance for control-critical tasks.
• Safety and Certifications: Compliance with industry-specific safety standards (e.g., SIL, UL) may be mandatory.

These factors heavily influence the suitability of different embedded system approaches.

Spectrum of Embedded Solutions for Industry

Let’s compare the common options, ranging from accessible components to fully industrialized systems:

1. Accessible Microcontrollers & Single-Board Computers (Arduino, ESP32, STM32, Raspberry Pi)

These platforms, often originating from the maker or consumer space, provide powerful capabilities at low cost but require careful consideration and often additional engineering effort for reliable industrial deployment.

General Strengths:

• Low unit cost.
• Rapid prototyping and development cycles.
• Large communities and extensive software libraries.
• High flexibility and customization.

General Industrial Limitations:

• Often lack native industrial temperature ranges and environmental protection.
• May have limited long-term availability guarantees.
• Susceptibility to electrical noise without proper shielding and circuit design.
• SD card reliance (Raspberry Pi) can be a failure point.
• May lack necessary industrial certifications out-of-the-box.

Use Cases: Suitable for less critical applications, prototyping, cost-sensitive projects where environmental conditions are controlled, or when integrated into a larger system with appropriate hardening (e.g., custom enclosure, power filtering, robust software design).

• Arduino: Best for simple, low-speed I/O, basic sensing, and tasks where processing power is minimal.
• ESP32: Excellent for IoT connectivity (Wi-Fi/BLE), low-power applications, and tasks requiring moderate processing.
• STM32 (and similar MCUs like NXP, TI): Strong contenders for real-time control, applications needing robust peripherals (CAN, industrial Ethernet), and when developers can select industrial-grade variants and implement robust board designs.
• Raspberry Pi: Ideal for applications needing a Linux environment, complex processing, sophisticated HMIs, networking gateways, or machine learning at the edge, but requires careful consideration of SD card reliability and thermal management.

2. Industrial System-on-Modules (SoMs)

Description: Compact boards containing the core processor, memory, power management, and often key peripherals, designed to be integrated onto a custom carrier board. Vendors like Toradex, Kontron, Advantech offer industrial-grade SoMs.

Strengths:

• Combines processing power (often ARM Cortex-A or Intel Atom) with industrial ratings.
• Guaranteed long-term availability.
• Simplifies complex high-speed board design (DDR memory routing, etc.).
• Allows customization via the carrier board for specific I/O needs.
• Often come with robust Board Support Packages (BSPs).

Limitations:

• Requires custom carrier board design expertise.
• Higher cost than component-level MCUs/SBCs.
• Development complexity can be higher than integrated platforms.

Best Applications: Custom embedded devices requiring significant processing power, specific I/O configurations, long product lifecycles, and industrial environmental ratings.

3. Industrial PCs (IPCs)

Description: Ruggedized computers designed specifically for industrial environments, often featuring fanless designs, wide temperature ranges, robust enclosures, and reliable storage options (e.g., industrial SSDs).

Strengths:

• High processing power (often x86-based).
• Runs standard operating systems (Windows IoT, Linux).
• Extensive connectivity options (multiple Ethernet, serial ports, USB).
• Designed for harsh environments and long-term reliability.
• Easier integration with enterprise systems and software.

Limitations:

• Higher cost and power consumption compared to MCUs/SoMs.
• Less suitable for hard real-time control tasks compared to dedicated MCUs or PLCs without specific RTOS configurations.
• Larger physical footprint.

Best Applications: Data aggregation gateways, complex HMI stations, machine vision processing, edge computing platforms requiring significant resources, running SCADA software locally.

4. Programmable Logic Controllers (PLCs)

Description: The traditional workhorse of industrial automation. Highly integrated, ruggedized systems with a focus on deterministic real-time control, extensive I/O capabilities, and standardized programming environments (IEC 61131-3).

Strengths:

• Extremely robust and reliable, designed for decades of operation.
• Deterministic real-time performance.
• Modular I/O expansion.
• Standardized programming languages familiar to industrial technicians.
• Built-in industrial networking (Profinet, EtherNet/IP, etc.).
• Safety-rated versions available.

Limitations:

• Generally lower processing power for complex computations compared to IPCs or high-end SBCs.
• Proprietary development environments and higher software costs.
• Less flexible for non-standard communication or complex algorithms compared to PC-based systems.
• Higher initial cost per I/O point compared to some component-level solutions.

Best Applications: Machine control, process automation, safety systems, applications requiring high reliability, determinism, and integration with standard industrial automation infrastructure.

Decision Framework: Matching the Platform to the Need

Use these key criteria to guide your selection:

1. Real-Time Requirements: Does the application require microsecond/millisecond precision and deterministic execution? (Favors PLCs, MCUs like STM32) Or is task completion time less critical? (Allows RPi, IPCs).
2. Environmental Conditions: What are the temperature, vibration, dust/moisture, and EMI conditions? (Favors PLCs, IPCs, Industrial SoMs; requires significant hardening for others).
3. Processing Load: Simple logic, complex algorithms, data analysis, or graphical HMI? (Simple: Arduino/ESP32; Moderate: STM32/ESP32; High: RPi, SoMs, IPCs).
4. Connectivity Needs: What communication protocols are required (Industrial Ethernet, Fieldbus, Wireless, Serial)? (PLCs/IPCs have strong native support; others require add-ons or specific variants).
5. Development Resources: What is the team’s expertise, budget, and timeline? (Faster/cheaper prototyping: Arduino, RPi, ESP32; Requires more specialized skills/budget: PLCs, SoMs, IPCs).
6. Longevity & Support: How long must the system operate, and is long-term component availability critical? (Favors PLCs, IPCs, Industrial SoMs).
7. Certifications: Are specific safety or industry certifications required? (Easier to achieve with pre-certified industrial platforms like PLCs/IPCs).
8. Total Cost of Ownership (TCO): Consider not just unit cost but development, integration, hardening, maintenance, and potential downtime costs.

Hybrid Architectures: The Best of Both Worlds

Often, the most effective industrial systems combine different types of embedded platforms:

• PLC + HMI: A PLC handles critical real-time control, while an IPC or Raspberry Pi provides a sophisticated graphical interface for operators.
• MCU + Gateway: Low-cost MCUs (like ESP32 or STM32) gather sensor data locally, transmitting it via wireless or wired protocols to a central IPC or RPi gateway for aggregation, analysis, and cloud communication.
• SoM + Custom I/O: An industrial SoM provides the core processing, connected to a custom carrier board with specialized sensor interfaces or actuators managed by simpler co-processing MCUs.

This leverages the strengths of each platform: the reliability and determinism of industrial hardware for control, and the processing power or connectivity features of other platforms for data handling and interfaces.

Conclusion: Choosing Wisely for Industrial Success

Selecting the right embedded system is fundamental to the success of any industrial application. While accessible platforms like Arduino, ESP32, STM32, and Raspberry Pi offer compelling entry points and flexibility, their deployment in demanding industrial settings requires careful engineering for environmental hardening, electrical robustness, and software reliability.

For applications demanding high reliability, long operational life, harsh environmental tolerance, or specific certifications, industrial-grade solutions like PLCs, IPCs, and specialized SoMs often provide a lower total cost of ownership despite higher initial costs.

A thorough analysis of your technical requirements, environmental constraints, development resources, and long-term operational needs using a structured decision framework will guide you to the most appropriate platform or hybrid architecture, ensuring a robust, reliable, and maintainable industrial embedded system.