How To Make Mini PLC using ESP8266 Node MCU

Introduction

A Programmable Logic Controller (PLC) is an automated control system that uses electronic and computer technology to control inputs and outputs of industrial processes. It reduces human intervention, increases efficiency, reduces human errors, and offers real-time data analysis. PLCs became popular after the 1970s, and they are widely used today. However, mini PLCs or compact PLCs are becoming more popular as they can be used in smaller processes, and they are much cheaper than full-sized PLCs. One of the technologies that can be used to create a mini PLC is ESP8266 Node MCU.

Explanation of How To Make Mini PLC

ESP8266 Node MCU:

ESP8266 Node MCU is a Wi-Fi enabled microcontroller. It consists of a programmable microcontroller, Wi-Fi module, and other support components. It is based on the ESP8266 Wi-Fi chip, which is a low-cost and low-power chip. The ESP8266 Node MCU can be programmed through the Arduino IDE, which is easy to use and widely popular. It has 11 GPIO pins, one ADC pin, and a USB interface. The Wi-Fi module supports 802.11 b/g/n protocol and can be used as both a access point or a station.

In this article you will learn how to make mini PLC using an ESP8266 (Node MCU ). Our PLC has 4 optically isolated digital inputs active high pins, 4 relay outputs and 1 open collector PWM output, and 1 analog (10 bit 0-5V) inputs . LEDs are used to indicate the status of output.

**How To Make Mini PLC ESP8266 Node MCU**

Circuit Diagram

of How To Make Mini PLC with ESP8266 Node MCU

This project can be designed using a few basic components. The circuit diagram of this project is shown below.

How To Make Mini PLC ESP8266 Node MCU Circuit Diagram — **Mini PLC ESP8266 Node MCU Circuit Diagram**

More Circuit Layouts

**120W Power Amplifier TDA7294 Circuit Diagram**

D718 B688 Class-AB Amplifier Circuit Diagram — **120W Power Amplifier TDA7294 Circuit Diagram**

**Variable Power Supply 0-30V_10A Circuit Diagram**

Stereo Amplifier TDA7297 Dual-Bridge Circuit Diagram — **Variable Power Supply 0-30V_10A Circuit Diagram**

Components List of How To Make Mini PLC

Following is the list of all components used in this project:

1 X ESP8266 Board
4X PC817 Opocoupler
5X BC547 Transistors
4 X LEDS
4 X 100 Ohm Resistors
11 X 1k Resistors
10 X 10k Resistors
4x 5V Relay
1X 2 Pin Terminal Block
6X 3 Pin Terminal Blocks
JUMPER WIRES

Project Zip File:

Gerber File:

How To Make Mini PLC using ESP8266 Node MCU:

To make a mini PLC using ESP8266 Node MCU, we need several components and tools. Below is a step-by-step guide on creating this project.

Step 1: Gather the components

Gather all the components required in this project. A complete list is already provided above in Components List section.

Step 2: Connect the Relay Module

The relay module is used to turn on and turn off devices. It requires a power supply of 5V and a controlling signal. Connect the power supply to the VCC and GND pins of the relay module. Then connect the relay module to the ESP8266 Node MCU. Connect the control pin of the relay to any GPIO pin of the Node MCU through a transistor BC547 according to the circuit diagram provided above.

Step 3: Connect the LED

The LED is used to inform the user if the device is turned on or off. Connect the LED to any GPIO pin of the Node MCU through BC547 transistor and connect it to a resistor. The resistor is used to limit the current in the LED.

Step 4: Write the Code

The code is used to control the relay and the LED. The code is written in Arduino IDE. Open the Arduino IDE and create a new sketch. Write the logic for turning on and off the relay and the LED. The code should also include the Wi-Fi connection and the web server. You can download the entire code needed for this project, from the link given above in the Components List section.

Step 5: Test the Mini PLC

Connect the power supply and turn on the mini PLC. Connect to the Wi-Fi hotspot created by the Node MCU. Open a web browser and access the IP address of the Node MCU. You should be able to control the relay and the LED through the web server.

Conclusion of How To Make Mini PLC

ESP8266 Node MCU is a powerful technology that can be used to create a mini PLC. The ESP8266 Wi-Fi chip enables the mini PLC to be controlled remotely. The mini PLC is easy to build and can be used to control small industrial processes. The mini PLC can be used in home automation, IoT applications, and hobby projects.