Week 8 - Journal

Development and Implementation Process

For implementation, I assembled the physical circuit by following the designed connections. After ensuring all components were securely placed, I uploaded the Arduino code via the Arduino IDE. The Bluetooth module was used to establish wireless communication, while the GUI allowed users to send commands to the Arduino.

Component Connections:

1. Bluetooth Module (HC-05/HC-06)
   
   

   • VCC → 5V (Arduino)

   • GND → GND (Arduino)

   • TX → RX (Pin 10) (Arduino)

   • RX → TX (Pin 11) (Arduino) (Use a voltage divider if needed to step down from 5V to 3.3V)

2. Servo Motor
   
   

   • VCC (Red Wire) → 5V (Arduino)

   • GND (Black Wire) → GND (Arduino)

   • Signal (Yellow Wire) → Pin 9 (Arduino)

3. Buzzer
   
   

   • Positive (Long Leg) → Pin 8 (Arduino)

   • Negative (Short Leg) → GND (Arduino)

4. Breadboard (Used to manage connections and provide a stable circuit layout.)
   
   

5. Jumper Wires (Used for connections between components and Arduino.)
   
   

6. USB Cable (Used to upload the code to the Arduino and provide power.)
   
   

To test the system:

1. I used a Bluetooth terminal app on a mobile device to send commands ('O' for open and 'C' for close).

2. The servo motor responded to these commands by changing its position.

3. The buzzer was activated momentarily when the servo moved.

4. The system was tested multiple times to ensure proper function and debugging was done as needed.

This approach ensured that the project was successfully implemented, allowing for a remote-controlled servo and buzzer using Bluetooth communication.

Explanation of the Arduino Code

This Arduino code allows you to control a servo motor and a buzzer wirelessly using a Bluetooth module (HC-05/HC-06). The system receives commands ('O' to open, 'C' to close) via Bluetooth, moves the servo motor, and triggers the buzzer.

Code Breakdown:

1. Including the Servo Library

#include <Servo.h>

• The Servo.h library is included to control the servo motor.

• This library simplifies positioning the servo by specifying an angle (0° to 180°).

2. Defining Variables and Pins

Servo myServo;  // Create a Servo object

char command;   // Variable to store received Bluetooth command

#define BUZZER 8 // Define the buzzer pin

#define SERVO_PIN 9 // Define the servo pin

#define BLUETOOTH_TX 10 // TX pin of Bluetooth module (Connect to RX of HC-05)

#define BLUETOOTH_RX 11 // RX pin of Bluetooth module (Connect to TX of HC-05)

• myServo: Creates a servo object to control the motor.

• command: A variable to store the received Bluetooth command.

• BUZZER (Pin 8): Digital pin connected to the buzzer.

• SERVO_PIN (Pin 9): Digital pin connected to the servo motor.

• BLUETOOTH_TX (Pin 10) and BLUETOOTH_RX (Pin 11): Defines the pins where the Bluetooth module is connected.

3. Setup Function (Runs Once at Startup)

void setup() {

    Serial.begin(9600); // Start serial communication

    myServo.attach(SERVO_PIN); // Attach the servo to pin 9

    pinMode(BUZZER, OUTPUT); // Set buzzer pin as output

    digitalWrite(BUZZER, LOW); // Initially turn off the buzzer

}

• Serial.begin(9600): Starts serial communication at 9600 baud rate for Bluetooth communication.

• myServo.attach(SERVO_PIN): Links the servo object to pin 9.

• pinMode(BUZZER, OUTPUT): Sets the buzzer pin as an output.

• digitalWrite(BUZZER, LOW): Ensures the buzzer is OFF at startup.

4. Loop Function (Runs Continuously)

void loop() {

    if (Serial.available()) {  // Check if data is available from Bluetooth

        command = Serial.read();  // Read the received character

        Serial.println(command);  // Print the command for debugging

• Serial.available(): Checks if a Bluetooth command has been received.

• Serial.read(): Reads the incoming character ('O' or 'C') and stores it in command.

• Serial.println(command): Prints the received command to the Serial Monitor for debugging.

5. Checking the Received Command

       if (command == 'O') {  // 'O' opens the servo

            myServo.write(90);  // Move servo to 90 degrees

            digitalWrite(BUZZER, HIGH); // Turn on buzzer

            delay(1000); // Keep buzzer on for 1 second

            digitalWrite(BUZZER, LOW); // Turn off buzzer

        } 

• If the received command is 'O', it:

  • Moves the servo to 90° (open position).

  • Turns on the buzzer.

  • Keeps the buzzer on for 1 second.

  • Turns the buzzer off.

6. Closing the Servo

       else if (command == 'C') {  // 'C' closes the servo

            myServo.write(0);  // Move servo back to 0 degrees

        }

    }

}

• If the received command is 'C', it:

  • Moves the servo back to 0° (closed position).

  • The buzzer does not activate in this case.

How It Works

1. The Bluetooth module receives a signal from a mobile app or PC.

2. The Arduino reads the received character via Bluetooth.

3. If the command is:

   • 'O': The servo opens to 90°, and the buzzer beeps for 1 second.

   • 'C': The servo closes to 0°.

4. The loop continues waiting for new commands.