Servo Motor Control with Potentiometer and Arduino

In this project, we will learn how to control the position of a Servo Motor using a Potentiometer. By turning the knob of the potentiometer, we can precisely move the servo arm from 0 to 180 degrees.

How it Works

The Potentiometer acts as an analog input. The Arduino reads the voltage (0V to 5V) and converts it into a digital value between 0 and 1023. Since a servo motor moves between 0 and 180 degrees, we use the map() function in our code to convert the input value into a degree value.

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Components Required

• Arduino Uno
• Servo Motor (e.g., SG90)
• Potentiometer (10k Ohm)
• Capacitors (100µF)
• Breadboard
• Jumper Wires
• External Power Supply (Recommended for servos to prevent Arduino resets)

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Circuit and Connection (Step-by-Step)

Based on the wiring diagram:

1. Potentiometer:
   • Left Pin: Connect to GND.
   • Middle Pin (Wiper): Connect to Arduino Analog Pin A0.
   • Right Pin: Connect to 5V.
2. Servo Motor:
   • Brown/Black Wire: Connect to GND.
   • Red Wire: Connect to Positive (+) of the Power Supply.
   • Orange/Yellow Wire (Signal): Connect to Arduino Digital Pin 9.
3. Power Supply:
   • Ensure the GND of the external power supply is connected to the Arduino GND (Common Ground).

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The Code

Copy and paste this code into your Arduino IDE:

#include <Servo.h>

Servo myservo;  // Create servo object to control a servo
int potpin = 0; // Analog pin used to connect the potentiometer (A0)
int val;        // Variable to read the value from the analog pin

void setup() {
  myservo.attach(9);  // Attaches the servo on pin 9 to the servo object
}

void loop() {
  val = analogRead(potpin);            // Reads potentiometer (0 to 1023)
  val = map(val, 0, 1023, 0, 180);     // Scale it for the servo (0 to 180)
  myservo.write(val);                  // Move the servo to the scaled position
  delay(15);                           // Small delay to allow the servo to move
}

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Understanding the Code

• #include <Servo.h>: This imports the library that allows Arduino to talk to the servo easily.
• analogRead(potpin): This reads the position of the knob.
• map(val, 0, 1023, 0, 180): This is the "brain" of the code. It converts the large potentiometer number into a servo angle.
• myservo.write(val): This sends the final angle command to the motor.

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Troubleshooting Tips

• Servo Jittering: Ensure you are using a separate power supply. Small servos can pull more current than the Arduino's USB port can handle.
• No Movement: Double-check the "Common Ground" (connecting external GND to Arduino GND).