How To Make ESP32 PLC (Programmable Logic Controller)

he ESP32 PLC is a powerful, low-cost automation controller designed for industrial and DIY projects. With the ESP32 PLC, you can control motors, sensors, and relays using Wi-Fi or Bluetooth. This ESP32 PLC supports multiple inputs and outputs, making it ideal for smart factory systems. Whether you’re building home automation or industrial monitoring, the ESP32 PLC offers reliability and easy programming. Integrate the ESP32 PLC with Modbus or MQTT protocols for seamless communication.

The ESP32 PLC is compatible with Arduino IDE and MicroPython, allowing flexible coding. Using ESP32 PLC modules, you can create scalable and energy-efficient systems. The ESP32 PLC ensures real-time control and IoT connectivity for engineers and hobbyists alike. Experience advanced automation with the ESP32 PLC and simplify your industrial projects.

Video Tutorial

Introduction

In modern industrial automation, ESP32 PLC systems are gaining attention for their versatility, cost-effectiveness, and ease of customization. Traditional PLCs are reliable but often expensive and closed-source, limiting their flexibility for educational and small-scale industrial applications. The ESP32-based programmable logic controller bridges this gap by combining the powerful dual-core ESP32 microcontroller with the robustness of industrial control logic.

This integration allows engineers, hobbyists, and developers to design smart automation systems with built-in Wi-Fi and Bluetooth capabilities, making remote monitoring and IoT connectivity easier than ever. With its modular design, support for multiple I/O configurations, and compatibility with standard PLC programming methods, the ESP32 controller offers a practical entry point into both industrial control and IoT-based automation.

Materials for the Project

1. 1. 10 × PC817 Optocoupler
   2. 10 × MOC3021 Optocoupler
   3.  10 × BT136 TRIAC
   4. 10x Red LED
   5.  10x Yellow LED
   6. 1x 1000uF 50V Capacitor
   7. 20 × 100Ω Resistor
   8. 10 × 220Ω Resistors
   9.  10 × 1 kΩ Resistors
   10.  12x 2-Pin Terminal Blocks
   11. Jumper Wires

Useful Tools 

ESP32 Pinout.

Notes:

• PWM: Any GPIO except input-only pins can be used for PWM (relay control, LEDs).

• ADC: GPIOs 32–39 for analog sensors.

• Boot-sensitive Pins: GPIO 0, 2, 12, 15 – avoid driving high during boot unless intentional.

• Relay/Output Control: Use GPIO 4, 5, 16, 17 for safe switching.

• Voltage Limits: ESP32 GPIO pins are 3.3V max. Never exceed.

⚙️How to Program:

You can program the ESP32 in two ways:

Option 1: Arduino IDE (Manual Control Logic)

Use digitalWrite() to turn loads ON/OFF based on sensors, timers, etc.

#define RELAY_PIN 23

void setup() {
pinMode(RELAY_PIN, OUTPUT);
}

void loop() {
digitalWrite(RELAY_PIN, HIGH); // Turn ON load
delay(1000);
digitalWrite(RELAY_PIN, LOW); // Turn OFF load
delay(1000);
}

Option 2: OpenPLC for Ladder Programming

• Install OpenPLC Editor on your PC

• Write ladder logic (NO/NC contacts, coils)

• Compile for ESP32 using OpenPLC firmware

• Upload via USB or WiFi

✅Advantages of ESP32 PLC with SSR:

• Silent operation (no clicks like mechanical relays)

• High-speed switching

• Durable (no moving parts)

• Compact & reliable

• WiFi and Bluetooth support

• Suitable for industrial-grade projects

Applications:

• Smart home automation

• Industrial process control

• IoT systems

• Timed irrigation or motor control

• Energy-efficient automation systems

Download Gerber Files

Gerber Files