Programming Arduino Mini PLC with Visuino Software

Learn how to program an Arduino Mini PLC with Visuino, a visual programming software for Arduino boards. This complete step-by-step guide covers setup, wiring, and project creation to help you easily control your PLC inputs and outputs using pulse generators.

Introduction

In this project, we’ll explore how to program an Arduino Mini PLC using Visuino, a powerful and intuitive visual programming tool designed for Arduino and other development boards.

The Arduino Mini PLC is a compact automation controller featuring multiple opto-isolated inputs and relay outputs. By using Visuino, you can quickly build control logic without writing a single line of code  ideal for automation beginners and professionals alike.

This tutorial will walk you through:

• Understanding the hardware setup

• Installing and using Visuino

• Creating pulse generator control logic

• Uploading your program to the Mini PLC

Components Required (BOM)

Circuit Diagram

[Insert circuit diagram image here]

The Arduino Mini PLC features five opto-isolated digital inputs and four relay outputs:

• Inputs (Opto-isolated): D2, D3, D4, D5, D6

• Relay Outputs: D7, D8, D11, D12

Each input is safely isolated to protect the Arduino from high voltage signals, while the relay outputs can directly switch AC or DC loads.

Understanding the Programming Process

Visuino simplifies Arduino programming through a drag-and-drop interface.
Instead of writing C++ code, you can visually connect logic components, timers, sensors, and outputs. The software automatically generates and uploads the code to your Arduino board.

In this project, we’ll start by creating a pulse generator circuit to test all four relay outputs.

Step-by-Step Build Guide

Step 1. Install and Open Visuino

Download and install Visuino from Visuino.com.
Launch the software after installation.

Step 2. Select the Board

In Visuino, select Arduino Nano (or your specific Mini PLC variant) as your board from the “Select Board” window.
Then, choose the correct processor and COM port under the Build tab.

Step 3. Add a Pulse Generator

Open the Toolbox tab and drag a Pulse Generator component into the workspace.
This block will produce a square wave output signal used to drive a relay.

Step 4. Connect the Output Pin

Connect the output of the Pulse Generator to digital pin D7, which is the first relay output on the Mini PLC.

Step 5. Adjust the Frequency

In the Properties window (on the left), adjust the frequency of the Pulse Generator.
This determines how fast the relay will toggle between ON and OFF.

Step 6. Upload the Program

Click on the Upload button in Visuino.
The program will compile and be sent to your Arduino Mini PLC. Once completed, the first relay should start switching according to the pulse signal.

Step 7. Add More Pulse Generators

Now, duplicate the first Pulse Generator three times to create four in total.
Connect each output to:

• D7

• D8

• D11

• D12

Adjust each generator’s frequency slightly so that each relay toggles at different rates.

Step 8. Upload the New Program

After connecting all outputs and adjusting their parameters, upload the updated program to your Mini PLC.
You’ll see all four relays blinking in sequence according to their respective pulse signals.

Step 9. Create Input-Controlled Logic

Now let’s make another program to control outputs using inputs instead of pulse generators.
Replace the pulse generator blocks with digital input blocks, connecting them to D2–D6.
Then connect these inputs to corresponding relay outputs (D7–D12).

Upload the code — now, your PLC outputs will activate only when their linked inputs are triggered.

Step 10. Test Your Setup

After uploading, test each input by applying a small signal.
Each input should activate its corresponding relay, confirming that the PLC logic is working correctly.

Working Explanation

Here’s how the setup works:

• Inputs (D2–D6) receive logic signals from sensors or buttons.

• Relays (D7–D12) switch loads like motors or lamps.

• Pulse Generators create periodic signals that automatically toggle relays for testing or simulation.

• Visuino converts your visual configuration into Arduino C++ code automatically, making programming seamless.

This is an excellent starting point for anyone who wants to learn how PLC automation works using Arduino-based hardware.

Advantages of Using Visuino for PLC Programming

• No coding required: Simply connect functional blocks visually.

• Fast prototyping: Ideal for quick automation concepts.

• Real-time parameter tuning: Change pulse frequencies and logic parameters easily.

• Supports multiple Arduino boards: Works with Uno, Nano, Mega, and custom Mini PLCs.

Applications

This Visuino-programmed Arduino Mini PLC can be used for:

• Industrial automation prototypes

• DIY home automation systems

• Relay-based motor control

• Sequential light or motor switching

• Learning visual PLC programming concepts

Troubleshooting Tips

• If the relays do not activate, check the COM port and board selection.

• Ensure power supply to the relay module is stable.

• Verify that the Pulse Generator output is connected to the correct digital pins.

• Reinstall the Visuino USB driver if the upload fails.

Conclusion

Programming an Arduino Mini PLC with Visuino allows you to automate tasks without writing complex code.
It’s a simple yet powerful way to explore industrial control systems, test automation logic, or create educational projects.

With a few clicks, you can control multiple relays, inputs, and devices — all visually.
For more Arduino and PLC-based tutorials, visit SekhoHub.online and explore our library of electronics and automation projects.

FAQs

1. What is Visuino?
Visuino is a visual programming environment that lets users create Arduino projects without coding by connecting graphical components.

2. Can I use other boards besides Arduino Nano?
Yes, Visuino supports many Arduino boards including Uno, Mega, Leonardo, and ESP32.

3. What is an Arduino Mini PLC?
It’s a compact version of an industrial PLC built around Arduino hardware, equipped with opto-isolated inputs and relay outputs.

4. Can I connect sensors to this PLC?
Absolutely! You can connect sensors like IR modules, PIR sensors, or switches to the input terminals.

5. Does Visuino require an internet connection?
No, once installed, Visuino works offline. You only need an internet connection for downloading the software or libraries.