Circuit Documentation

Summary

This circuit is designed to control two DC motors using an Arduino UNO microcontroller board, interfaced with an L298N DC motor driver. The system is capable of receiving commands via a Bluetooth HC-06 module, allowing for wireless control of the motors. The motors are powered by a 4xAA battery pack, which also supplies 12V to the motor driver. The Arduino UNO controls the motor driver by sending signals to dictate the direction and speed of the motors.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• It has 14 digital input/output pins, 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header, and a reset button.

Motor Amarillo Motorreductor Hobby (x2)

• A yellow hobby gear motor
• It operates on a typical voltage, suitable for interfacing with the L298N motor driver.

L298N DC Motor Driver

• A high-power motor driver capable of driving up to 4 DC motors or 2 stepper motors.
• It has 4 output channels and can provide a continuous current of 2A to each channel.

Bluetooth HC-06

• A wireless Bluetooth transceiver module
• It allows for serial communication over Bluetooth.

4xAA Battery Holder

• A battery holder for four AA batteries
• It provides a power source for the motors and the motor driver.

Wiring Details

Arduino UNO

• 5V connected to Bluetooth HC-06 VCC
• GND connected to Bluetooth HC-06 GND, L298N GND, and 4xAA battery holder NEG
• D13 connected to L298N IN4
• D12 connected to L298N IN3
• D11 connected to L298N ENB
• D5 connected to L298N IN2
• D4 connected to L298N IN1
• D3 connected to L298N ENA
• D1 (TX) connected to Bluetooth HC-06 RXD
• D0 (RX) connected to Bluetooth HC-06 TXD

Motor Amarillo Motorreductor Hobby

• First motor vcc connected to L298N OUT2
• First motor GND connected to L298N OUT1
• Second motor vcc connected to L298N OUT4
• Second motor GND connected to L298N OUT3

L298N DC Motor Driver

• GND connected to Arduino UNO GND and 4xAA battery holder NEG
• IN3 connected to Arduino UNO D13
• IN4 connected to Arduino UNO D12
• ENB connected to Arduino UNO D11
• IN2 connected to Arduino UNO D5
• IN1 connected to Arduino UNO D4
• ENA connected to Arduino UNO D3
• OUT1 and OUT2 connected to the first Motor Amarillo Motorreductor Hobby
• OUT3 and OUT4 connected to the second Motor Amarillo Motorreductor Hobby
• 12V connected to 4xAA battery holder POS

Bluetooth HC-06

• VCC connected to Arduino UNO 5V
• GND connected to Arduino UNO GND
• TXD connected to Arduino UNO D0 (RX)
• RXD connected to Arduino UNO D1 (TX)

4xAA Battery Holder

• POS connected to L298N 12V
• NEG connected to Arduino UNO GND and L298N GND

Documented Code

/*
 * Control 4 DC motors with Smartphone via bluetooth
 */
  
int motor1Pin1 = 4;
int motor1Pin2 = 5; 
int enable1Pin = 3; 
int motor2Pin1  = 12; 
int motor2Pin2 = 13;
int enable2Pin = 11; 
int state;
int flag=0;        
int stateStop=0;

void setup() {
    // sets the pins as outputs:
    pinMode(motor1Pin1, OUTPUT);
    pinMode(motor1Pin2, OUTPUT);
    pinMode(enable1Pin,  OUTPUT);
    pinMode(motor2Pin1, OUTPUT);
    pinMode(motor2Pin2, OUTPUT);
    pinMode(enable2Pin, OUTPUT);
    // sets enable1Pin and enable2Pin high so that motor can turn on:
    digitalWrite(enable1Pin, HIGH);
    digitalWrite(enable2Pin, HIGH);
    // initialize serial communication at 9600 bits per second:
    Serial.begin(9600);
}

void loop() {
    if(Serial.available() > 0){     
      state = Serial.read();   
      flag=0;
    }   
    // if the state is 'F' the DC motor will go forward
    if (state == 'F') {
        digitalWrite(motor1Pin1, HIGH);
        digitalWrite(motor1Pin2, LOW); 
        digitalWrite(motor2Pin1, LOW);
        digitalWrite(motor2Pin2, HIGH);
        if(flag == 0){
          Serial.println("Go Forward!");
          flag=1;
        }
    }
    
    // if the state is 'R' the motor will turn left
    else if (state == 'R') {
        digitalWrite(motor1Pin1, HIGH); 
        digitalWrite(motor1Pin2, LOW); 
        digitalWrite(motor2Pin1, LOW);
        digitalWrite(motor2Pin2, LOW);
        if(flag == 0){
          Serial.println("Turn LEFT");
          flag=1;
        }
        delay(1000);
        state=3;
        stateStop=1;
    }
    // if the state is 'S' the motor will Stop
    else if (state == 'S' || stateStop == 1) {
        digitalWrite(motor1Pin1, LOW); 
        digitalWrite(motor1Pin2, LOW); 
        digitalWrite(motor2Pin1, LOW);
        digitalWrite(motor2Pin2, LOW);
        if(flag == 0){
          Serial.println("STOP!");
          flag=1;
        }
        stateStop=0;
    }
    // if the state is 'L' the motor will turn right
    else if (state == 'L') {
        digitalWrite(motor1Pin1, LOW); 
        digitalWrite(motor1Pin2, LOW); 
        digitalWrite(motor2Pin1, LOW);
        digitalWrite(motor2Pin2, HIGH);
        if(flag == 0){
          Serial.println("Turn RIGHT");
          flag=1;
        }
        delay(1000);
        state=3;
        stateStop=1;
    }
    // if the state is 'B' the motor will Reverse
    else if (state == 'B') {
        digitalWrite(motor1Pin1, LOW); 
        digitalWrite(motor1Pin2, HIGH);
        digitalWrite(motor2Pin1, HIGH);
        digitalWrite(motor2Pin2, LOW);
        if(flag == 0){
          Serial.println("Reverse!");
          flag=1;
        }
    }
    //For debugging purpose
    Serial.println(state);
}

This code is designed to be uploaded to the Arduino UNO microcontroller. It sets up the necessary pins as outputs and initializes serial communication. The loop function reads the state from the Bluetooth module and controls the motors accordingly. The commands 'F', 'R', 'S', 'L', and 'B' are used to control the motors' movements: forward, turn left, stop, turn right, and reverse, respectively.