CIRCUIT DIAGRAM
Wireless control plays an important role in modern robotics. Bluetooth technology offers a simple, low-cost, and efficient way to control devices over short distances.
In this project, a smartphone acts as a remote controller. Commands such as forward, backward, left, right, and stop are sent from a mobile app to the robot via Bluetooth. The microcontroller processes these commands and controls the motors using a motor driver.
Key Features :
- Wireless control using Bluetooth
- Mobile phone–based operation
- Simple and user-friendly interface
- Low cost and easy to implement
This project is ideal for beginners learning robotics and wireless communication.
Connection Description (Wiring Map)
Main Components :
- Microcontroller: Arduino Uno / Nano / ESP32
- Bluetooth Module: HC-05 / HC-06
- Motor Driver: L298N / L293D
- DC Motors: For robot movement
- Chassis & Wheels
Power Supply: Battery (9V / 12V / Li-ion)
Wiring Summar
Component | Arduino Pin | Description |
Bluetooth TX | D2 | Connected to Arduino RX (Software Serial) |
Bluetooth RX | D3 | Connected to Arduino TX (via voltage divider) |
Motor Driver IN1 | D4 | Left motor control |
Motor Driver IN2 | D5 | Left motor control |
Motor Driver IN3 | D6 | Right motor control |
Motor Driver IN4 | D7 | Right motor control |
Motor Driver ENA/ENB | Jumper / PWM pins | Motor speed control |
Motor Driver VCC | Battery + | Motor power |
Arduino VCC | 5V | Logic power |
Common GND | GND | Shared ground |
Motor Connection:
- Left motor → Motor driver OUT1 & OUT2
- Right motor → Motor driver OUT3 & OUT4
Working Principle
- Mobile app sends control commands via Bluetooth.
- Bluetooth module receives data and sends it to Arduino through serial communication.
- Arduino interprets commands (F, B, L, R, S).
- Motor driver activates motors accordingly.
- Robot moves in the desired direction.
Testing the Hardware
- Bluetooth Test
- Pair mobile phone with HC-05 module
- Check LED status for successful pairing
- Pair mobile phone with HC-05 module
- Motor Driver Test
- Run motors individually to verify direction and speed
- Run motors individually to verify direction and speed
- Command Test
- Send commands from mobile app
- Observe robot response for each command
- Send commands from mobile app
- Full System Test
( Control robot movement wirelessly using phone )
Applications :
- Educational robotics
- Surveillance robots (with upgrades)
- Home automation control
- Remote-controlled vehicles
Troubleshooting
Problem | Possible Cause | Solution |
Bluetooth not pairing | Wrong password or power issue | Check default password (1234/0000) |
Robot not moving | Motor driver wiring issue | Verify motor and driver connections |
Erratic movement | Weak battery | Recharge or replace battery |
Bluetooth disconnected | Out of range | Keep within 10 meters |
Motors rotate wrong direction | Polarity reversed | Swap motor wires |
( A Bluetooth Controlled Robot is a wireless robotic system that can be controlled using a mobile phone through Bluetooth communication. The robot receives commands from a mobile application and moves accordingly. This project demonstrates wireless control, embedded systems, and basic robotics concepts. It is widely used for learning automation, robotics, and short-range wireless communication. )