Section outline

  • Project – Arduino-Based Robotic Arm

    This project brings your robotic arm design to life using an Arduino board and servo motors. The goal is to build a functional 4DOF robotic arm capable of performing basic movements such as picking up and placing small objects. It involves assembling the hardware, wiring the servos, writing Arduino code, and testing motion sequences.

    • Hardware Requirements

      • Arduino Uno or Nano
      • 4x Servo motors (with sufficient torque for your design)
      • Power supply (external 5V adapter or battery for servos)
      • Jumper wires and servo extension cables
      • Breadboard (optional, for power distribution)
      • Base and structural parts (custom-built or 3D printed)

      Wiring the Servos

      Each servo has three wires: Signal (usually yellow or white), VCC (red), and GND (black or brown). Wire them as follows:

      • Connect all GNDs to the Arduino GND or external supply GND.
      • Connect all VCCs to a regulated 5V source (do not power servos directly from Arduino).
      • Connect each Signal wire to a digital PWM pin on the Arduino, such as pins 3, 5, 6, and 9.

      Use a common ground between Arduino and external power to ensure reliable signal control.

    • Arduino Code Overview

      Here is a basic example of how to control multiple servos using the Servo.h library:

      
#include <Servo.h>

Servo baseServo;
Servo shoulderServo;
Servo elbowServo;
Servo gripperServo;

void setup() {
  baseServo.attach(3);
  shoulderServo.attach(5);
  elbowServo.attach(6);
  gripperServo.attach(9);
}

void loop() {
  baseServo.write(90);         // Center base
  shoulderServo.write(45);     // Lift arm
  elbowServo.write(120);       // Extend
  gripperServo.write(30);      // Close gripper
  delay(1000);

  gripperServo.write(90);      // Open gripper
  delay(1000);
}

      You can create sequences by combining different angles and delays to simulate tasks like pick-and-place.

      Motion Sequences and Calibration

      • Start by testing each servo individually to verify wiring and power.
      • Use the Serial Monitor to receive angle inputs for manual control.
      • Create smooth transitions using for loops and delays.

      Calibrate each joint for range of motion and fine-tune servo angles to avoid mechanical stress or jitter.

      Project Extensions

      • Add a potentiometer-based joystick for manual control.
      • Use push buttons to trigger predefined arm movements.
      • Integrate a small display (like OLED) to show current arm status or mode.

      By the end of this project, you will have a fully working robotic arm that showcases real-world application of servo control, mechanical design, and embedded programming—all fundamental skills for any aspiring roboticist.