ESP32 Joystick Data Receiver for Robot Control

Overview

This project features an ESP32-based joystick data receiver integrated with a ROS 2 joy_serial_bridge package. The system enables control of a 4-wheeled drive robot equipped with a flywheel shooting mechanism, an adjustable angle motor, and a servo. The joystick axes and button inputs are processed and mapped to control the robot's motors and mechanisms.

Features

• Joystick Input Parsing: Receives joystick data in the format "axes;buttons" via ROS and parses it.
• 4-Wheeled Drive Control: Maps joystick axes to control forward, backward, left, and right movement.
• Flywheel Shooting Mechanism: Activates flywheel motors via specific joystick buttons.
• Servo Control: Adjusts servo position using joystick buttons.
• Angle Adjustment: Uses a dedicated motor to change the flywheel's shooting angle based on joystick input.
• Dynamic Feedback: Debugging information is printed to the serial monitor, including axis values, button states, and robot actions.

System Components

Hardware

1. ESP32 Microcontroller
2. 4 DC Motors for Driving
3. 2 Motors for Flywheel Shooting Mechanism
4. 1 Motor for Angle Adjustment
5. 1 Servo for fine control
6. Joystick Controller

ROS 2 Package

• joy_serial_bridge: Bridges joystick input /joy from ROS to serial data sent to the ESP32.

Installation

Prerequisites

1. ROS 2 (Humble or jazzy or later)

2. Python dependencies for ROS packages:

   sudo apt install python3-serial

3. Hardware Setup:

   • Connect the ESP32 to a computer via USB.
   • Wire the motors, servo, and flywheel mechanism according to your robot's design.

Setting Up ROS Workspace

1. Create a ROS workspace:

   mkdir -p ~/joy_serial_ws/src
   cd ~/joy_serial_ws/src
   ros2 pkg create --build-type ament_python joy_serial_bridge

2. Add joy_serial_bridge code to the newly created package and build:

   cd ~/joy_serial_ws
   colcon build --packages-select joy_serial_bridge
   source install/setup.bash

3. Verify package visibility:

   ros2 pkg list | grep joy_serial_bridge

Upload ESP32 Code

1. Open the Arduino IDE and load the joy_serial_receiver.ino file provided in this repository.
2. Configure the serial monitor baud rate to 115200.
3. Upload the code to the ESP32.

Usage

Starting ROS 2 Nodes

1. Start the joystick node:

   ros2 run joy joy_node --ros-args -p deadzone:=0.0

2. Echo the joystick data:

   ros2 topic echo /joy

3. Start the joy_serial_bridge:

   ros2 run joy_serial_bridge joy_to_serial --ros-args -p dev:=/dev/ttyUSB0 -p baud:=115200

Robot Control

• Driving: Use the left joystick to control forward, backward, left, and right movement.
• Flywheel Shooting: Activate the flywheel motors using the assigned button.
• Angle Adjustment: Adjust the shooting angle using the corresponding joystick axis.
• Servo Control: Fine-tune shooting angle using the servo control buttons.

Debugging

Monitor joystick inputs and robot actions via the Arduino Serial Monitor or an alternative terminal:

sudo apt install minicom

minicom -D /dev/ttyUSB0 -b 115200

You should see parsed joystick data and corresponding robot actions.

Notes

1. Adjust the axis/button mappings in the ESP32 code (joy_serial_receiver.ino) to suit your robot's control requirements.
2. Ensure your motors and servo are configured correctly for the ESP32 pins.