How to Make an Arduino Bluetooth Controlled Car | Easy DIY Tutorial

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Introduction

In this section, introduce the project by explaining what an Arduino Bluetooth Controlled Car is. Highlight that it’s a smart car built using an Arduino microcontroller and controlled wirelessly via Bluetooth from a smartphone. Mention the popularity of DIY tech and robotics among beginners and enthusiasts. Emphasize that by following this tutorial, readers will be able to create their very own Bluetooth Controlled Car at home using affordable components.

We have made one same project before too but this time we have added some more feature. like horn and led bulb which can also control by the mobile app. We are going to share all the detail like code, circuit and application. if you wanna learn we are sharing all the detail here.

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What You’ll Need

List all the necessary hardware and tools needed to build the Bluetooth Controlled Car. Include detailed descriptions of each component to help beginners understand their purpose.

Required Components Bluetooth Controlled Car

Arduino Uno or Nano (acts as the brain of the car)
HC-05 or HC-06 Bluetooth Module (enables wireless communication).
L298N Motor Driver Module (controls the motors)
4 DC motors with wheels
Car chassis (the frame of the car)
Power supply (12v lipo battery)
Jumper wires and breadboard (for connections)
HC-05 or HC-06 Bluetooth Module: Wireless Communication Hub
The HC-05 and HC-06 Bluetooth modules provide seamless wireless connectivity between the car and a smartphone. These modules use serial communication (UART) to interface with the Arduino.
HC-05: Can be used in both master and slave mode.
HC-06: Functions only in slave mode.
We connect the module’s TX pin to Arduino’s RX and RX to Arduino’s TX, ensuring proper communication flow. Power is supplied via 3.3V or 5V depending on the breakout board’s specifications.
Once connected, we can use mobile apps like Arduino Bluetooth Controller or Bluetooth Terminal to send movement commands—forward, backward, left, and right—directly from our phone to the car.

L298N Motor Driver Module: Dual Motor Control
The L298N Motor Driver acts as a bridge between Arduino and the motors, allowing us to control the speed and direction of each motor independently. This dual H-bridge driver supports two DC motors with up to 2A of current per channel.
Key connections:
IN1 to IN4: Connected to Arduino digital pins for motor control.
ENA and ENB: Enable motor A and B, can be connected to PWM pins for speed control.
12V input: Power from the LiPo battery.
With this module, we can:
Control two motors independently
Drive the car forward, backward, and turn
Use PWM for speed modulation
Its built-in heat sink ensures reliable operation during prolonged use.

4 DC Motors with Wheels: Precision Mobility
To ensure smooth and responsive movement, we use four DC motors, each paired with a durable rubber wheel. These motors convert electrical energy into mechanical motion, propelling the car in different directions.
Characteristics:
Operate on 6V–12V DC
Typically rated for 100–300 RPM
Provide sufficient torque for movement on various surfaces
Using four motors (one per wheel) offers improved stability and traction, making our car capable of navigating tight turns and uneven paths effectively.
Each motor is securely mounted on the chassis and connected to the L298N module for controlled operation.

Car Chassis: The Structural Frame
The chassis forms the base of our robotic vehicle, providing structural integrity and component mounting space. It is typically made of acrylic, plastic, or lightweight aluminum for optimal durability and weight balance.
Chassis features:
Pre-drilled mounting holes for motors and components
Multiple tiers for better organization of electronics
Designed to house battery, motor driver, and Arduino safely
It is essential to ensure that the chassis layout allows proper airflow around components and easy access to wiring. Most DIY chassis kits come with metal brackets and screws for quick assembly.

Power Supply: Reliable 12V LiPo Battery
A powerful and stable power source is critical. We use a 12V LiPo battery to deliver sufficient voltage to all electronic modules and motors.
Why a LiPo battery?
Delivers high current output
Compact and lightweight
Rechargeable with a longer lifespan
We connect the battery’s output to the L298N module, which powers both the motors and the Arduino (through its 5V regulated output). Always ensure:
A battery protection circuit is used
Proper voltage regulation is in place to avoid damage
This battery ensures our car can run for extended periods without performance drops.

Jumper Wires and Breadboard: Easy and Flexible Wiring
To connect all components, we rely on jumper wires and a mini breadboard for prototyping and circuit layout. These tools make wiring easy, allowing quick changes during testing.
Best practices:
Use color-coded wires for clarity (red for power, black for ground)
Ensure firm connections to avoid short circuits
Use heat shrink tubing or zip ties to manage cable clutter
A soldered setup is recommended for final builds, but for testing and prototyping, breadboards and jumper wires offer unparalleled flexibility.

Mention where to buy these components and tips for choosing compatible parts.

Arduino UNO –BUY LINK
Arduino UNO cable –BUY LINK
Bluetooth Module HC-05 –BUY LINK
Jumper Wires –BUY LINK
Chassis –BUY LINK
L298N Motor Driver –BUY LINK
12V Battery –BUY LINK
Wheel –BUY LINK
BO motor –BUY LINK
you can buy full components kit for this projects

HC-05 Datasheet

Bluetooth Controlled Car Circuit

This part walks through how to assemble the Arduino Bluetooth Controlled Car step by step. Include a wiring diagram showing how the motors connect to the L298N motor driver, and how both the motor driver and Bluetooth module connect to the Arduino.

Provide detailed, numbered instructions with helpful tips to ensure proper connections. Discuss the importance of proper power supply and wire management.

Connection Table

Arduino UNO	L298N Motor Driver
12 Pin	IN 1
11 Pin	IN 2
10 Pin	IN 3
9 Pin	IN 4
Arduino UNO	HC-05 Bluetooth
( +5V )	VCC
GND	GND (
TX Pin	RX Pin
RX Pin	TX Pin
Arduino UNO	9 V Battery	L298N Motor Driver
( +5V )		+5 Volt
	9 Volt	+12 Volt
GND	GND	GND
Motor 1, 2	Motor 3, 4	L298N Motor Driver
Terminal 1		Out 1
Terminal 2		Out 2
	Terminal 1	Out 3
	Terminal 2	Out 4

Section 3: Programming the Arduino

Guide readers through uploading the Arduino code that will allow the car to respond to Bluetooth commands. Provide clean, beginner-friendly code with comments explaining each part — particularly how the Arduino reads signals from the Bluetooth module and activates the motors.

Include a download link or GitHub repository for the full code. Mention the use of the Arduino IDE and how to connect the board via USB for uploading.

Bluetooth Controlled Car Code

//Techatronic.com
char m=0;
void setup() 
{
pinMode(9, OUTPUT);  
pinMode(10, OUTPUT);
pinMode(11, OUTPUT);
pinMode(12, OUTPUT);
pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
pinMode(7, OUTPUT);

Serial.begin(9600);
}
void loop() 
{
 if (Serial.available()>0)
 {
  m=Serial.read();
  Serial.println(m);
  }
 if (m=='R')
{digitalWrite(5, HIGH);
  digitalWrite(9, HIGH);
  digitalWrite(10, LOW);
  digitalWrite(11, HIGH);
  digitalWrite(12, LOW);
  }

  else if (m=='L')
{
  digitalWrite(5, HIGH);
  digitalWrite(9, LOW);
  digitalWrite(10, HIGH);
  digitalWrite(11, LOW);
  digitalWrite(12, HIGH);
  }

else if (m=='F')
{
digitalWrite(6, HIGH);
  digitalWrite(7, HIGH);
  digitalWrite(9, HIGH);
  digitalWrite(10, LOW);
  digitalWrite(11, LOW);
  digitalWrite(12, HIGH);
  
  }

 else if (m=='B')
{
digitalWrite(6, HIGH);
  digitalWrite(7, HIGH);
  digitalWrite(9, LOW);
  digitalWrite(10, HIGH);
  digitalWrite(11, HIGH);
  digitalWrite(12, LOW);
  
  }

else if (m=='S')
{

digitalWrite(5, LOW);
  digitalWrite(6, LOW);
  digitalWrite(7, LOW);
  digitalWrite(9, LOW);
  digitalWrite(10, LOW);
  digitalWrite(11, LOW);
  digitalWrite(12, LOW);
  } 
}

How to use Application

Download the application BT Controller apk file
Intstall the software into your mobile phone
Go to the bluetooth setting and pair new device
select HC-05 and enter the password 1234
Now open the application and click on the setting icon
connect car to hc-05
Now you can use the application

Section 4: Creating the Smartphone Control App

Show readers how to control the Bluetooth Controlled Car using a smartphone. Recommend free apps from the Play Store like:

Bluetooth Terminal
Arduino Bluetooth Controller
MIT App Inventor (for custom apps)

Provide screenshots or examples of how to pair the phone with the HC-05 module (default PIN: 1234 or 0000), and demonstrate which commands to send (e.g., “F” for forward, “B” for backward).

Section 5: Testing and Troubleshooting

Explain how to test the finished Arduino Bluetooth Controlled Car. Break down each function to verify (e.g., does the car move forward when you press “F”?). Provide a checklist of common issues like:

Motors not turning
Bluetooth not pairing
Wrong power connections
Incorrect command recognition

Offer simple troubleshooting tips for each problem.

Keywords Used: Bluetooth Controlled Car troubleshooting, Arduino car not working, HC-05 issues, Arduino Bluetooth debugging

Section 6: Upgrades and Customization Ideas

Encourage readers to improve their Bluetooth Controlled Car project. Some ideas include:

Adding obstacle detection with ultrasonic sensors (HC-SR04)
Making a custom app with a joystick layout
Integrating voice control or gesture recognition
Using rechargeable Li-ion batteries with a charging module

This helps the blog stay relevant to both beginners and advanced users.

Keywords Used: Arduino Bluetooth Car upgrades, smart Bluetooth Controlled Car, DIY car customization, Arduino innovation projects

Conclusion

Summarize what was accomplished: building a functional Arduino Bluetooth Controlled Car from scratch. Reinforce that this is a beginner-friendly yet rewarding DIY project. Encourage readers to share their builds, post questions in the comments, and subscribe or follow for more tutorials.

Keywords Used: Build your own Arduino Bluetooth Controlled Car, complete Bluetooth Controlled Car tutorial, Arduino beginner project