The prototyping trap is familiar: an engineer glues together an elegant control system on an Arduino or ESP32, it behaves perfectly on the bench — and then fails on the factory floor. This article explains the practical thresholds where microcontroller-based solutions stop being appropriate and why a programmable logic controller (PLC) becomes the correct engineering choice.
The hardware divide: robustness vs. flexibility
Input/Output (I/O) voltages and signal integrity
Most MCUs operate at logic levels of 3.3 V or 5 V (TTL/CMOS). Those levels are fine for short, controlled interconnects on a workbench, but they are vulnerable to voltage drops, ground loops, and induced noise when the wiring runs meters across a plant. Industrial control syste ...
