View source for Experiment 3: Interfacing Potentiometer for Position Control Simulation

== Experiment 3: Interfacing Potentiometer for Position Control Simulation ==

'''Objective:'''  
To simulate position control by using a potentiometer as analog input to drive a servo motor.  

'''Task:'''  
# Connect potentiometer to Arduino analog input and servo to PWM output.  
# Map the potentiometer values to servo angles.  
# Observe servo position change as potentiometer is rotated.

<span style="background-color: #ffcccc; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
⚠️ Disconnect your Arduino from the computer while making or removing component connections.
</span>

<span style="background-color: #ffff99; display: inline-block; padding: 5px; border-radius: 5px;">
<strong>⚠️ Important Note:</strong><br>
1. Connect only the Arduino Uno (without any component connections) to the computer via USB.<br>
2. Upload the code to the Arduino.<br>
3. Disconnect the Arduino from the computer and remove the USB cable.<br>
4. Make all component connections using patch cords as per the circuit diagram.<br>
5. Then connect the 9V adapter to provide external power supply to the Arduino.
</span>

=== Circuit Diagram (without LCD) ===
[[File:Eecit-kit-03-circuit.png|center|thumb|400px|Circuit Diagram]]

=== Circuit Diagram (with LCD) ===
[[File:Servo-lcd.png|center|thumb|400px|Circuit Diagram]]

=== Board Connections (without LCD) ===
[[File:Eecit-kit-03-board-connection.png|center|thumb|400px|Board Connections]]

=== Arduino Connections (without LCD) ===
{| class="wikitable" style="text-align:center;"
! Component !! Arduino Pin  
|-
| Potentiometer Output || A0  
|-
| Servo Signal || D8/(PWM)  
|}

=== Important ===
Before uploading your Arduino code, make sure you have installed the following libraries in the Arduino IDE:
1.Servo.h : for Servo motor control

<span style="background-color: #FEAD5E; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
✅ Install via:
</span>

<span style="background-color: #FEAD5E; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
Sketch → Include Library → Manage Libraries → Search and Install “Servo” by Michael Margolis, Arduino
</span>

<span style="background-color: #FFECA1; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
✅ Verify : 
</span>

<span style="background-color: #FFECA1; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
Sketch → Include Library → The included library name should be present
</span>

=== Code ===
<pre>
// © 2025, Cognifront. Member of The IoT Kits Family.

// Experiment 3: Interfacing Potentiometer for Position Control Simulation

// Define the analog pin connected to the potentiometer
const int Pot = A0;

// Include the Servo library to control servo motors
#include <Servo.h>

// Create a Servo object to control a servo motor
Servo myservo;

void setup() {
  pinMode(Pot, INPUT);            // Optional: analogRead sets pin mode automatically
  myservo.attach(8);              // Attach the servo signal wire to digital pin 8
  
  Serial.begin(9600);             // Start serial communication for monitoring
  Serial.println("Potentiometer to Servo Angle Control");
  Serial.println("==================================");
}

void loop() {
  // Read the potentiometer value (0 to 1023 from ADC)
  int potVal = analogRead(Pot);

  // Map potentiometer range (0–1023) to servo range (0–180 degrees)
  int angle = map(potVal, 0, 1023, 0, 180);

  // Set the servo to the calculated angle
  myservo.write(angle);

  // Display potentiometer value and corresponding angle
  Serial.print("Potentiometer Value: ");
  Serial.print(potVal);
  Serial.print("   |   Servo Angle: ");
  Serial.println(angle);

  // Short delay to allow the servo to move smoothly
  delay(100);
}

</pre>

=== Board Connections (with LCD) ===
[[File:Board-diagram.png|center|thumb|400px|Board Connections]]


=== Arduino Connections (with LCD I2C) === 
{| class="wikitable" style="text-align:center;"
! Component !! Arduino Pin  
|-
| Potentiometer Output || A0  
|-
| Servo Signal (PWM) || D8  
|-
| LCD VCC || 5V  
|-
| LCD GND || GND  
|-
| LCD SDA || A4  
|-
| LCD SCL || A5  
|}

=== Important ===
Before uploading your Arduino code, make sure you have installed the following libraries in the Arduino IDE:

1. Wire.h – For I²C communication between Arduino and peripheral devices.

2. LiquidCrystal_I2C.h – For controlling LCD displays using the I²C interface.

<span style="background-color: #E7DDFF; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
✅ Install via (ZIP Method):
</span>

<span style="background-color: #E7DDFF; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
Sketch → Include Library → Add .ZIP Library → Select Downloaded .zip File → Open → Wait for “Library Installed” message
</span>

<span style="background-color: #FFECA1; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
✅ Verify : 
</span>

<span style="background-color: #FFECA1; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
Sketch → Include Library → The included library name should be present
</span>

3. Servo.h : for Servo motor control

<span style="background-color: #FEAD5E; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
✅ Install via:
</span>

<span style="background-color: #FEAD5E; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
Sketch → Include Library → Manage Libraries → Search and Install “Servo” by Michael Margolis, Arduino
</span>

<span style="background-color: #FFECA1; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
✅ Verify : 
</span>

<span style="background-color: #FFECA1; display: inline-block; padding: 5px; border-radius: 5px; font-weight: bold;">
Sketch → Include Library → The included library name should be present
</span>

<pre>
// © 2025, Cognifront. Member of The IoT Kits Family.
// Experiment 3: Interfacing Potentiometer for Position Control Simulation
// Added: Display potentiometer value and servo angle on 16x2 I2C LCD

/*
  🔌 LCD CONNECTIONS (16x2 I2C Display with Arduino UNO)
  ------------------------------------------------------
  LCD Pin     →  Arduino Pin
  ----------------------------
  GND         →  GND
  VCC         →  5V
  SDA         →  A4   (I2C Data line)
  SCL         →  A5   (I2C Clock line)

  ⚙️ NOTE:
  - Most common I2C LCD addresses are 0x27 or 0x3F.
  - If no text appears, try changing the address in this line:
        LiquidCrystal_I2C lcd(0x27, 16, 2);
      to
        LiquidCrystal_I2C lcd(0x3F, 16, 2);
*/

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Servo.h>

// Initialize LCD with I2C address (0x27 by default), 16 columns, 2 rows
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Define potentiometer and servo pins
const int Pot = A0;    // Analog pin connected to potentiometer output (middle pin)
Servo myservo;         // Servo object

void setup() {
  pinMode(Pot, INPUT);             // Potentiometer input
  myservo.attach(8);               // Servo signal wire → D8 on Arduino

  Serial.begin(9600);              // For serial monitoring
  Serial.println("Potentiometer to Servo Angle Control");
  Serial.println("==================================");

  // Initialize the LCD
  lcd.init();                      // Start LCD
  lcd.backlight();                 // Turn on LCD backlight
  lcd.clear();

  // Display static text headers
  lcd.setCursor(0, 0);
  lcd.print("Pot: ");
  lcd.setCursor(0, 1);
  lcd.print("Angle: ");
}

void loop() {
  // Read the potentiometer value (0–1023)
  int potVal = analogRead(Pot);

  // Map potentiometer range to servo range (0–180 degrees)
  int angle = map(potVal, 0, 1023, 0, 180);

  // Move servo to calculated angle
  myservo.write(angle);

  // Show values on Serial Monitor
  Serial.print("Potentiometer Value: ");
  Serial.print(potVal);
  Serial.print("   |   Servo Angle: ");
  Serial.println(angle);

  // Display on LCD
  lcd.setCursor(5, 0);      // Position after "Pot: "
  lcd.print(potVal);
  lcd.print("   ");         // Clear trailing digits

  lcd.setCursor(7, 1);      // Position after "Angle: "
  lcd.print(angle);
  lcd.print((char)223);     // Degree symbol (°)
  lcd.print("   ");         // Clear trailing digits

  delay(100);               // Small delay for smooth motion
}

</pre>

=== Observation ===
* As the potentiometer knob is rotated, the servo motor smoothly changes its position.
* The servo angle corresponds proportionally to the potentiometer voltage input (0° to 180° mapped).

=== Conclusion ===
* A potentiometer can be used as an analog input device to control the angular position of a servo motor.
* This demonstrates how analog signals can be mapped to control actuators in real-time..

=== Real Life Example ===
Robotic Arm Joint Feedback: Potentiometers act as position sensors to measure rotation angles of robotic joints, enabling precise movement control and feedback in automation and mechatronics systems.