Precision Kinematics: Wireless Robot Arm Control

Robotic arms are the workhorses of modern manufacturing, providing precise movement through multiple "Degrees of Freedom" (DOF). This project bridges the gap between mechanical assembly and interactive software, allowing you to pilot a 4-DOF wood-kit robot arm using a custom-built Android application and an Arduino Uno.

4-DOF Mechanical Architecture

The robot arm utilizes four independent SG90 Micro-servo motors to simulate human-like articulated movement:

1. The Base (Rotation): Controls the horizontal orientation of the entire arm assembly.
2. The Shoulder (Elevation): Manages the primary height and reach.
3. The Elbow (Extension): Provides vertical articulation for positioning the robotic hand.
4. The Gripper (Claw): The "end-effector" responsible for picking up and releasing objects.

Wireless Serial Communication: HC-05 Integration

To enable long-range control without physical tethering, the project employs the HC-05 Bluetooth module.

• Packet Protocol: The Android app sends a stream of data packets (formatted strings or raw bytes) representing the desired angle (0-180 degrees) for each servo.
• Serial Parsing: The Arduino listens on its Serial buffer, parses the incoming characters, and uses the Servo.h library to write the exact PWM signal to the corresponding motor.
• Smooth Motion: The software includes interpolation logic to ensure the servos move fluidly rather than jumping between positions, protecting the structural integrity of the wooden frame.

Mobile App Development with Android Studio

The companion mobile app, developed in Android Studio, provides a professional-grade graphical interface. Featuring sliders or joysticks for each axis, it translates tactile user input into digital commands in real-time. This integration serves as a powerful introduction to mobile-hardware interfacing, a critical skill in the expanding "Internet of Robotic Things" (IoRT) field.

Usually robot can move by it self, but sometimes we need to control it. In this project I will control arm robot using smartphone. Arm robot there is a servo motor which is controlled through arduino. Arduino receives a command to move the servo from the data sent by the mobile application. like people who communicate remotely we need a wireless device, here I use Bluetooth so that Arduino and mobile applications can communicate.

COMPONENTS

1. Robot Arm Kit

2. Arduino Uno Rev 3

Arduino uno used to program input from the PIR sensor and sent to mobile phone

3. Bluetooth HC-05

Communication tool between arduino and mobile application.

4. Servo Tower Pro SG90

5. Mobile Application