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Wireless I/O Interfaces for Industrial Controllers: An Educational Approach

Armando Cordeiro, Felipe Morais Paulino


Due to technological advances, the need for versatile and flexible applications in the field of industrial automation is continuously growing. Digitalization, flexibility, connectivity, high-speed transmission, data analysis and integration of different systems are now requirements in most industries. Industrial communication networks are the main tool in accomplishing those requirements. The proposed work is focused in the development of a solution for collecting remote field signals and transmit them by wireless technology to a programmable logic controller (PLC) with fieldbus communication capabilities. Based on microcontrollers (Adafruit’s ESP32), the final architecture has a manager module, or Master, and two input and output digital and analogue (I/O) modules, or Slaves, which communicates through the native ESP-NOW wireless protocol of the microcontrollers. The I/O module consists of designed integrated circuits for collecting and sending field data through a Serial Peripheral Interface (SPI) with the microcontroller. I/O modules has galvanic isolated electronic circuits to adapt electrical signals into industrial standards. The manager module has an Ethernet interface module that allows connection to PLCs via the Modbus TCP/IP protocol.


Industrial Automation; I/O remote integration; SPI; ESP-NOW; Modbus TCP/IP; PLC.

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