Building a Simple Robotic Arm with Arduino, Servos, Joysticks, and 3d Printing

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.What You’ll Need:

1. Arduino Uno: The brain of your robotic arm, responsible for processing signals from the joysticks and controlling the servos.

2. 4 Servos: These are the motors that will move the robotic arm's joints. You'll need servos with enough torque to handle the arm's weight.

3. 2 Joysticks: These are used to control the arm’s movement along different axes.

4. Breadboard: Used for making temporary connections between components, ideal for prototyping.

5. Male-to-Male Jumper Wires: To connect the Arduino, breadboard, and servos.

6. 3D Printed Components: Custom-designed parts for the arm, such as brackets, joints, and links.

7. Power Supply: To ensure the servos receive enough power to function properly.

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.Understanding the Circuit Diagram

A clear and well-structured circuit diagram is essential for successfully assembling the robotic arm. It visually represents how each component is connected and ensures that power, signals, and ground are properly distributed across the setup.

Here’s a breakdown of the main connections:

• 
  Servos (x4):

  • Each servo has three wires — Signal, VCC (5V), and GND.

  • Connect the signal wires of the four servos to PWM digital pins on the Arduino (e.g., pins 3, 5, 7, 8).

  • Connect all servo VCC wires to a common 5V power supply 

  • Connect all GND wires to a common ground

• 
  Joysticks (x2):

  • Each joystick has two analog outputs (X and Y) and VCC/GND.

  • Connect X and Y outputs of Joystick 1 to A0 and A1 on the Arduino.

  • Connect X and Y outputs of Joystick 2 to A2 and A3 on the Arduino.

  • Connect VCC and GND of both joysticks to the Arduino’s 5V and GND.

• Breadboard:

  • Use a breadboard to distribute power (5V) and ground (GND) to all servos and joysticks easily.

  • Use male-to-male jumper wires to connect components from the Arduino to the breadboard and servos.

  
  

• Common Ground:

  • Ensure all grounds (Arduino, servos, joystick, power supply) are connected together. This is crucial for the circuit to function correctly.

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.How Does It Work?

In this project, the Arduino Uno reads input signals from the two joysticks. The analog readings are then mapped to appropriate servo angles to move the robotic arm. The four servos control different parts of the arm:

• Base rotation (turning the arm around its base)

• Shoulder movement (raising and lowering the arm)

• Elbow movement (bending the arm)

• Wrist movement (moving the wrist for picking or placing objects)

Additionally, the 3D-printed components help in structuring the arm, making it customizable to your needs.

Step-by-Step Breakdown:

1. Wiring the Servos:
   Each of the four servos will be connected to the Arduino Uno using PWM pins (pins 3,5,7 and 8). This allows for precise control over each servo’s movement.

2. Connecting the Joysticks:
   The two joysticks will each have two potentiometers—one for the X-axis and one for the Y-axis. The analog signals from the joysticks are sent to the Arduino’s analog input pins (A0 and A1 & A2 and A3
   ). The joystick movements will control the servo positions on the arm.

3. Using the Breadboard:
   The breadboard serves as a convenient platform for making temporary connections between the Arduino, servos, and joysticks. You’ll use male-to-male jumper wires to connect everything properly. The breadboard helps organize your connections and makes troubleshooting easier, especially during the prototyping phase.

4. 3D Printing the Components:
   Instead of using pre-made parts, you can design and 3D print custom components for the robotic arm, such as:

   • Joints: 3D print brackets to hold the servos in place and create joints for rotation and movement.

   • Links: Print the arm's structure, like forearms and upper arms, to connect the servos.

   • Mounts: Design custom mounts to securely attach the servos to the structure of the arm.

   3D printing gives you the flexibility to design parts tailored specifically to your needs, and it makes the overall project more customizable.

5. Programming the Arduino:
   The heart of this project lies in the programming. Using the Servo library in Arduino IDE, you’ll read the analog signals from the joysticks and translate them into servo movements. The code below demonstrates the basic structure for controlling the servos: -

          #include <Servo.h>

  

Servo servo1;

Servo servo2;

Servo servo3;

Servo servo4;

int joyX1 = 0;

int joyY1 = 1;

int joyX2 = 2;

int joyY2 = 3;

int servoVal1;

int servoVal2;

void setup() 

{

  servo1.attach(3);

  servo2.attach(5);

  servo3.attach(7);

  servo4.attach(8);

  servo1.write(0);

  servo2.write(0);

  servo3.write(0);

  servo4.write(0);

  Serial.begin(9600);

}

void loop()

{

  int x1 = analogRead(joyX1);

  servoVal1 = map(x1, 0, 1023, 0, 180);

  servo1.write(servoVal1);

  int y1 = analogRead(joyY1);

  servoVal1 = map(y1, 0, 1023, 70, 180);

  servo2.write(servoVal1);

  

  int x2 = analogRead(joyX2);

  servoVal2 = map(x2, 0, 1023, 0, 180);

  servo3.write(servoVal2);

  int y2 = analogRead(joyY2);

  servoVal2 = map(y2, 0, 1023, 70, 180);

  servo4.write(servoVal2);

  // Print joystick values to Serial Monitor

  Serial.print("x1: "); Serial.print(x1);

  Serial.print(", y1: "); Serial.print(y1);

  Serial.print(", x2: "); Serial.print(x2);

  Serial.print(", y2: "); Serial.println(y2);

  delay(15);  

}

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