Yun Shield – Toggle an LED using Arduino Uno with Proteus Simulation

Introduction

This microcontroller project demonstrates how to toggle an LED using an Arduino Uno and a Yun Shield, controlled from a mobile device. It is a simple but powerful introduction to Internet of Things (IoT) concepts using Proteus simulation and visual programming.
The project shows how physical hardware like an LED can be controlled remotely, making it ideal for beginners exploring embedded systems, DIY electronics, and IoT-based control systems.
By combining Arduino, IoTBuilder logic, and a clear workflow, this project delivers a clean learning experience without unnecessary complexity.

This Arduino IoT LED control example is ideal for beginners learning IoT-based embedded systems and mobile-controlled electronics.

How the Project Works (Overview)

The system uses an Arduino Uno connected to a Yun Shield, which acts as a bridge between a mobile device and the microcontroller.
An LED is connected to digital pin 13 of the Arduino. When a button is triggered from the mobile application, the Yun Shield sends a command to the Arduino.
The Arduino toggles the LED state (ON or OFF) based on the received trigger. The logic continuously updates the LED state, making real-time remote control possible.

Block Diagram / Workflow Explanation

The workflow of the project follows three main stages:

1. Setup Phase

   • Arduino pin 13 is configured as an OUTPUT.

   • The LED is initially turned OFF.

   • A debug message (“Hello World”) is sent to the Yun server for verification.

2. Idle Loop

   • The loop remains empty, waiting for external IoT triggers.

3. IoT Trigger Action

   • A mobile button (IotBtn1) triggers the event.

   • The LED state is toggled.

   • Arduino updates pin 13 accordingly.

   • The new LED state is reflected both physically and on the IoT interface.

This clean separation between setup, idle, and trigger-based execution makes the system easy to understand and modify.

Key Features

• Remote LED control using a mobile device

• Arduino Uno and Yun Shield integration

• IoT-based trigger system

• Real-time LED state toggling

• Simple digital output control

• Designed using Visual Designer for Arduino AVR

• Fully testable in Proteus simulation

Components Used

• Arduino Uno

• Yun Shield

• LED

• Resistors

• Power supply (+5V)

• Proteus simulation environment

Applications

• Smart home lighting control

• IoT learning and training projects

• Remote device control demonstrations

• Embedded systems education

• DIY electronics and prototyping

• Mobile-controlled automation systems

Explanation of Code (High-Level)

The firmware initializes digital pin 13 as an output to control the LED.
During setup, the LED is turned OFF, and a debug message is sent to confirm communication with the Yun server.
The main loop remains idle, relying entirely on IoT events.
When the mobile button trigger is received, the system toggles a Boolean state variable and updates the LED accordingly using digitalWrite.
This event-driven structure is efficient and well-suited for IoT applications.

Flowchart

Download FlowChart

Proteus Simulation

In the Proteus simulation, the Arduino Uno is connected to the Yun Shield module and an LED on pin 13.
When the IoT trigger is activated, the LED toggles between ON and OFF states instantly.
The simulation accurately reflects real hardware behavior, allowing testing and validation before physical deployment.

FAQs