🤖 Bluetooth Robot Controller

A simple and interactive mobile application developed using Flutter that allows users to wirelessly control a robot using Bluetooth communication with an Arduino + HC-05 module.

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📱 App Features

• Bluetooth Device Scanning: Lists all paired Bluetooth devices.
• Connect & Communicate: Connect to Arduino’s HC-05 module.
• Manual Control Panel:
  • Forward (F)
  • Backward (B)
  • Left (L)
  • Right (R)
  • Auto-stops after short movement unless held.
• Disconnect option returns user to device selection screen.
• User Feedback with Snackbars after sending commands.
• Designed with a clean, responsive, and modern UI.

⚠️ Note: Requires location & Bluetooth permissions. App targets Android 10+.

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⚙️ Technologies Used

• Flutter (Dart)
• flutter_bluetooth_serial for Bluetooth communication
• permission_handler for runtime permissions

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🛠️ Arduino Setup

Components Required:

• Arduino Uno
• HC-05 Bluetooth Module
• L298N Motor Driver
• 4 DC Motors (for robot movement)
• Power Supply (Battery pack)

HC-05 Wiring:

HC-05 Pin	Arduino Pin
VCC	5V
GND	GND
TXD	RX (D0)
RXD	TX (D1) (via Voltage Divider)

Use a voltage divider (e.g. 1kΩ + 2kΩ) between Arduino TX and HC-05 RX to avoid damaging the HC-05.

Arduino Sketch (Sample):

char command;

void setup() {
  Serial.begin(9600);
  pinMode(2, OUTPUT); // Left motor
  pinMode(3, OUTPUT); // Right motor
}

void loop() {
  if (Serial.available()) {
    command = Serial.read();

    switch (command) {
      case 'F': forward(); break;
      case 'B': backward(); break;
      case 'L': left(); break;
      case 'R': right(); break;
      case 'S': stopMotors(); break;
    }
  }
}

void forward() { digitalWrite(2, HIGH); digitalWrite(3, HIGH); }
void backward() { digitalWrite(2, LOW); digitalWrite(3, LOW); }
void left() { digitalWrite(2, LOW); digitalWrite(3, HIGH); }
void right() { digitalWrite(2, HIGH); digitalWrite(3, LOW); }
void stopMotors() { digitalWrite(2, LOW); digitalWrite(3, LOW); }

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