LED Control via ROS2 (Micro-ROS with ESP32)

Overview

This project demonstrates how to control an LED on an ESP32 using ROS2 (Micro-ROS). The ESP32 acts as a ROS2 node that subscribes to an Int32 message from the topic led_control. The received integer value (0 or 1) determines the LED state.

Hardware Requirements

• ESP32 Development Board
• LED (Optional, if using an external LED)
• USB Cable for programming

Software Requirements

• PlatformIO
• Micro-ROS library
• ROS2 installed on a PC

Code Explanation

• The ESP32 subscribes to the led_control topic.
• When a message is received, it controls the LED state based on the received value.
• Uses Micro-ROS for communication between ESP32 and ROS2.

Setup Instructions

1. Install Micro-ROS:

   • Follow the official Micro-ROS documentation to set up the environment for ESP32.
   • Install the required dependencies for Arduino or PlatformIO.

2. Upload the Code:

   • Connect the ESP32 to your PC.
   • Compile and upload the code using PlatformIO or Arduino IDE.

3. Run ROS2 Publisher:

   • Ensure ROS2 is installed on your PC.
   • Run the following command to publish LED state messages:

     ros2 topic pub /led_control std_msgs/msg/Int32 "{data: 1}"

     • Send 1 to turn the LED ON.
     • Send 0 to turn the LED OFF.

4. Monitor Serial Output:

   • Open the Serial Monitor at 115200 baud rate to observe received messages.

Function Breakdown

• setup():

  • Initializes the serial communication.
  • Configures the LED pin as an output.
  • Sets up Micro-ROS, creates a node, and subscribes to the led_control topic.

• subscription_callback():

  • Receives an integer value from ROS2.
  • Controls the LED state accordingly.
  • Prints the received data to the Serial Monitor.

• loop():

  • Executes the Micro-ROS executor to handle incoming messages.

Notes

• Ensure ROS2 is properly configured on your PC before running the publisher.
• Modify the LED_PIN macro if using a different GPIO for the LED.

References

• Micro-ROS Documentation
• ROS-2(Humble) Documentation