HM10 Bluetooth-Controlled Robot Car with Arduino and Dabble Gamepad

In this tutorial, you’ll learn how to set up and control a Bluetooth-controlled robot car using an Arduino, an HM-10 Bluetooth module, and a motor driver module. We’ll be using the Dabble app as a gamepad to control the movement of the robot.

Components Needed

• Arduino Uno
• HM-10 Bluetooth module
• L298N Motor Driver Module
• Four DC Motors
• 7-12V DC power supply
• Jumper wires
• Dabble app (Download link below)

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Step 1: Connect the Hardware Components

Add the wiring diagram here to help users follow the connections clearly.

1. Connect the Motors to the Motor Driver Module (L298N)
   • Right Motor 1 to OUT1 and OUT2 on the motor driver.
   • Right Motor 2 to OUT3 and OUT4 on the motor driver.
   • Left Motor 1 to OUT1 and OUT2 on the motor driver.
   • Left Motor 2 to OUT3 and OUT4 on the motor driver.
2. Connect the Motor Driver to Arduino
   • Connect IN1 on the motor driver to Arduino pin 7.
   • Connect IN2 on the motor driver to Arduino pin 8.
   • Connect IN3 on the motor driver to Arduino pin 9.
   • Connect IN4 on the motor driver to Arduino pin 10.
   • Connect the EN1 pin of the motor driver to Arduino pin 5.
   • Connect the EN2 pin of the motor driver to Arduino pin 6.
3. Power Connections
   • Connect the 7-12V DC power supply to the motor driver’s VCC and GND terminals.
   • Connect the motor driver’s GND to the Arduino’s GND for a common ground connection.
   • Connect the Arduino to your computer using a USB cable to upload the code.
4. Connect the Bluetooth Module (HM-10)
   • Connect the TX pin of the HM-10 to Arduino’s digital pin 2.
   • Connect the RX pin of the HM-10 to Arduino’s digital pin 3.
   • Connect VCC and GND of the HM-10 to the Arduino’s 5V and GND pins, respectively.

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Daigram

Step 2: Upload the Code

Use the following code to program your Arduino:

#define CUSTOM_SETTINGS
#define INCLUDE_GAMEPAD_MODULE
#include <Dabble.h>

// Right motor pins
int enableRightMotor = 5; 
int rightMotorPin1 = 7;
int rightMotorPin2 = 8;

// Left motor pins
int enableLeftMotor = 6;
int leftMotorPin1 = 9;
int leftMotorPin2 = 10;

void setup() {
  pinMode(enableRightMotor, OUTPUT);
  pinMode(rightMotorPin1, OUTPUT);
  pinMode(rightMotorPin2, OUTPUT);
  
  pinMode(enableLeftMotor, OUTPUT);
  pinMode(leftMotorPin1, OUTPUT);
  pinMode(leftMotorPin2, OUTPUT);

  rotateMotor(0, 0);   
  Dabble.begin(9600, 2, 3);  // Initialize Bluetooth communication
}

void loop() {
  int rightMotorSpeed = 0;
  int leftMotorSpeed = 0;
  
  Dabble.processInput();

  if (GamePad.isUpPressed()) {
    rightMotorSpeed = 255;
    leftMotorSpeed = 255;
  }

  if (GamePad.isDownPressed()) {
    rightMotorSpeed = -255;
    leftMotorSpeed = -255;
  }

  if (GamePad.isLeftPressed()) {
    rightMotorSpeed = 255;
    leftMotorSpeed = 0;
  }

  if (GamePad.isRightPressed()) {
    rightMotorSpeed = 0;
    leftMotorSpeed = 255;
  }

  rotateMotor(rightMotorSpeed, leftMotorSpeed);
}

void rotateMotor(int rightMotorSpeed, int leftMotorSpeed) {
  if (rightMotorSpeed < 0) {
    digitalWrite(rightMotorPin1, LOW);
    digitalWrite(rightMotorPin2, HIGH);    
  } else {
    digitalWrite(rightMotorPin1, HIGH);
    digitalWrite(rightMotorPin2, LOW);      
  }

  if (leftMotorSpeed < 0) {
    digitalWrite(leftMotorPin1, LOW);
    digitalWrite(leftMotorPin2, HIGH);    
  } else {
    digitalWrite(leftMotorPin1, HIGH);
    digitalWrite(leftMotorPin2, LOW);      
  }

  analogWrite(enableRightMotor, abs(rightMotorSpeed));
  analogWrite(enableLeftMotor, abs(leftMotorSpeed));    
}

• Open the Arduino IDE, paste the code, and upload it to the Arduino.
• Ensure the baud rate is set to 9600 for proper communication with the Bluetooth module.

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Step 3: Set Up the Dabble App

1. Download and Install Dabble
   Install the Dabble app on your smartphone from this link: Download Dabble App.
2. Pair the Bluetooth Module
   • Open the Dabble app on your phone.
   • Go to Settings in the app and turn on Bluetooth if it’s off.
   • Search for available devices, select your HM-10 module, and pair it with the phone.
3. Control the Robot with the Gamepad
   • In the Dabble app, go to Gamepad.
   • Use the directional buttons to control the robot’s movement:
     • Up for forward
     • Down for backward
     • Left for left turn
     • Right for right turn

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Troubleshooting Tips

• Motor Not Running: Check the power connections and ensure your battery provides enough voltage.
• Bluetooth Not Connecting: Confirm the HM-10 module is powered and the TX/RX pins are correctly connected.
• Response Delay: If the robot’s response is slow, ensure that the Dabble app’s baud rate matches the code (9600).

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