Circuit Documentation

Summary

This circuit is designed to control four DC motors using an Arduino 101 microcontroller, an L298N DC motor driver, and an HC-05 Bluetooth module. The motors are powered by a combination of 3.7V batteries and a 9V battery. The Bluetooth module allows for wireless control of the motors via commands sent from a paired device.

Component List

1. Arduino 101

   • Description: Microcontroller board based on the Intel Curie module.
   • Pins: A5/SCL, A4/SDA, AREF, GND, D13/SCK, D12/MISO, D11 PWM/MOSI, D10 PWM/SS, D9 PWM, D8, D7, D6 PWM, D5 PWM, D4, D3 PWM, D2, D1/TX, D0/RX, AIN, ioref, RESET, 3V3, 5V, VIN, A0, A1, A2, A3, ICSP MISO, ICSP SCK, ICSP MOSI

2. L298N DC Motor Driver

   • Description: Dual H-Bridge motor driver for controlling two DC motors.
   • Pins: OUT1, OUT2, 12V, GND, 5V, OUT3, OUT4, 5V-ENA-JMP-I, 5V-ENA-JMP-O, +5V-J1, +5V-J2, ENA, IN1, IN2, IN3, IN4, ENB

3. HC-05 Bluetooth Module

   • Description: Bluetooth module for wireless communication.
   • Pins: Key, VCC, GND, TXD, RXD, State

4. DC Motor

   • Description: Standard DC motor.
   • Pins: pin 1, pin 2

5. 9V Battery

   • Description: Standard 9V battery for powering the Arduino.
   • Pins: -, +

6. 3.7V Battery

   • Description: Standard 3.7V battery for powering the motor driver.
   • Pins: +, -

Wiring Details

Arduino 101

• GND: Connected to the GND pins of the L298N DC motor driver, HC-05 Bluetooth module, and the negative terminals of the 3.7V batteries and 9V battery.
• D10 PWM/SS: Connected to the ENB pin of the L298N DC motor driver.
• D9 PWM: Connected to the ENA pin of the L298N DC motor driver.
• D8: Connected to the IN1 pin of the L298N DC motor driver.
• D7: Connected to the IN2 pin of the L298N DC motor driver.
• D6 PWM: Connected to the IN3 pin of the L298N DC motor driver.
• D5 PWM: Connected to the IN4 pin of the L298N DC motor driver.
• D1/TX: Connected to the RXD pin of the HC-05 Bluetooth module.
• D0/RX: Connected to the TXD pin of the HC-05 Bluetooth module.
• 3V3: Connected to the VCC pin of the HC-05 Bluetooth module.
• 5V: Connected to the 5V pin of the L298N DC motor driver.
• VIN: Connected to the positive terminal of the 9V battery.

L298N DC Motor Driver

• GND: Connected to the GND pin of the Arduino 101 and the negative terminals of the 3.7V batteries.
• ENB: Connected to the D10 PWM/SS pin of the Arduino 101.
• ENA: Connected to the D9 PWM pin of the Arduino 101.
• IN1: Connected to the D8 pin of the Arduino 101.
• IN2: Connected to the D7 pin of the Arduino 101.
• IN3: Connected to the D6 PWM pin of the Arduino 101.
• IN4: Connected to the D5 PWM pin of the Arduino 101.
• OUT1: Connected to pin 1 of two DC motors.
• OUT2: Connected to pin 2 of two DC motors.
• OUT3: Connected to pin 2 of two DC motors.
• OUT4: Connected to pin 1 of two DC motors.
• 12V: Connected to the positive terminals of the 3.7V batteries.
• 5V: Connected to the 5V pin of the Arduino 101.

HC-05 Bluetooth Module

• RXD: Connected to the D1/TX pin of the Arduino 101.
• TXD: Connected to the D0/RX pin of the Arduino 101.
• VCC: Connected to the 3V3 pin of the Arduino 101.
• GND: Connected to the GND pin of the Arduino 101.

DC Motors

• Motor 1 (pin 1): Connected to OUT1 of the L298N DC motor driver.
• Motor 1 (pin 2): Connected to OUT2 of the L298N DC motor driver.
• Motor 2 (pin 1): Connected to OUT1 of the L298N DC motor driver.
• Motor 2 (pin 2): Connected to OUT2 of the L298N DC motor driver.
• Motor 3 (pin 1): Connected to OUT4 of the L298N DC motor driver.
• Motor 3 (pin 2): Connected to OUT3 of the L298N DC motor driver.
• Motor 4 (pin 1): Connected to OUT4 of the L298N DC motor driver.
• Motor 4 (pin 2): Connected to OUT3 of the L298N DC motor driver.

9V Battery

• -: Connected to the GND pin of the Arduino 101.
• +: Connected to the VIN pin of the Arduino 101.

3.7V Batteries

• -: Connected to the GND pin of the Arduino 101 and the L298N DC motor driver.
• +: Connected to the 12V pin of the L298N DC motor driver.

Documented Code

#include <SoftwareSerial.h>

// Pin definitions for L298N motor driver
const int ENA = 9;  // PWM pin for motor A
const int IN1 = 8;  // Control pin 1 for motor A
const int IN2 = 7;  // Control pin 2 for motor A
const int ENB = 10; // PWM pin for motor B
const int IN3 = 6;  // Control pin 1 for motor B
const int IN4 = 5;  // Control pin 2 for motor B

// Bluetooth module pins
const int BT_RX = 2; // Bluetooth module TX to Arduino RX
const int BT_TX = 3; // Bluetooth module RX to Arduino TX

SoftwareSerial bluetooth(BT_RX, BT_TX);

void setup() {
  // Initialize motor control pins as outputs
  pinMode(ENA, OUTPUT);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(ENB, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);

  // Initialize serial communication for Bluetooth
  Serial.begin(9600);
}

void loop() {
  if (Serial.available() > 0) {
    char command = Serial.read();

    switch (command) {
      case 'F': // Move forward
        moveForward();
        break;
      case 'B': // Move backward
        moveBackward();
        break;
      case 'L': // Turn left
        turnLeft();
        break;
      case 'R': // Turn right
        turnRight();
        break;
      case 'S': // Stop
        stopMotors();
        break;
      default:
        // Unknown command
        break;
    }
  }
}

void moveForward() {
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  analogWrite(ENA, 255); // Full speed

  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
  analogWrite(ENB, 255); // Full speed
}

void moveBackward() {
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  analogWrite(ENA, 255); // Full speed

  digitalWrite(IN3, LOW);
  digitalWrite(IN4, HIGH);
  analogWrite(ENB, 255); // Full speed
}

void turnLeft() {
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  analogWrite(ENA, 255); // Full speed

  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
  analogWrite(ENB, 255); // Full speed
}

void turnRight() {
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  analogWrite(ENA, 255); // Full speed

  digitalWrite(IN3, LOW);
  digitalWrite(IN4, HIGH);
  analogWrite(EN