Circuit Documentation

Summary

This circuit is designed to control a robot using an ESP32 microcontroller, an L298N motor driver, and IR sensors for obstacle detection. The robot is powered by a 12V power supply and a 9V battery. The ESP32 reads inputs from the IR sensors and controls the motors via the L298N driver to navigate the robot.

Component List

1. ESP32 (30 pin)

   • Description: A powerful microcontroller with built-in Wi-Fi and Bluetooth capabilities.
   • Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, Vin, D23, D22, TX0, RX0, D21, D19, D18, D5, TX2, RX2, D4, D2, D15, 3V3

2. L298N DC Motor Driver

   • Description: A dual H-bridge motor driver that allows control of 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. DC Motor

   • Description: A simple DC motor.
   • Pins: pin 1, pin 2

4. IR Sensor

   • Description: An infrared sensor used for obstacle detection.
   • Pins: out, gnd, vcc

5. 7805 Voltage Regulator

   • Description: A voltage regulator that outputs a stable 5V.
   • Pins: Vin, Gnd, Vout

6. 12V Power Supply

   • Description: A power supply providing 12V.
   • Pins: +, -

7. 9V Battery

   • Description: A battery providing 9V.
   • Pins: +, -

Wiring Details

ESP32 (30 pin)

• 3V3: Connected to vcc of both IR sensors and + of the 9V battery.
• GND: Connected to gnd of both IR sensors, - of the 9V battery, GND of the 12V power supply, GND of the L298N motor driver, and Gnd of the 7805 voltage regulator.
• D34: Connected to out of the first IR sensor.
• D35: Connected to out of the second IR sensor.
• D25: Connected to ENA of the L298N motor driver.
• D26: Connected to IN1 of the L298N motor driver.
• D27: Connected to IN2 of the L298N motor driver.
• D14: Connected to ENB of the L298N motor driver.
• D12: Connected to IN3 of the L298N motor driver.
• D13: Connected to IN4 of the L298N motor driver.
• Vin: Connected to Vout of the 7805 voltage regulator.

L298N DC Motor Driver

• ENA: Connected to D25 of the ESP32.
• IN1: Connected to D26 of the ESP32.
• IN2: Connected to D27 of the ESP32.
• ENB: Connected to D14 of the ESP32.
• IN3: Connected to D12 of the ESP32.
• IN4: Connected to D13 of the ESP32.
• OUT1: Connected to pin 1 of the first DC motor.
• OUT2: Connected to pin 2 of the first DC motor.
• OUT3: Connected to pin 1 of the second DC motor.
• OUT4: Connected to pin 2 of the second DC motor.
• 12V: Connected to + of the 12V power supply.
• GND: Connected to GND of the 12V power supply and GND of the ESP32.

DC Motor

• First Motor
  • pin 1: Connected to OUT1 of the L298N motor driver.
  • pin 2: Connected to OUT2 of the L298N motor driver.
• Second Motor
  • pin 1: Connected to OUT3 of the L298N motor driver.
  • pin 2: Connected to OUT4 of the L298N motor driver.

IR Sensor

• First Sensor
  • vcc: Connected to 3V3 of the ESP32.
  • gnd: Connected to GND of the ESP32.
  • out: Connected to D34 of the ESP32.
• Second Sensor
  • vcc: Connected to 3V3 of the ESP32.
  • gnd: Connected to GND of the ESP32.
  • out: Connected to D35 of the ESP32.

7805 Voltage Regulator

• Vin: Connected to + of the 12V power supply.
• Gnd: Connected to - of the 12V power supply and GND of the ESP32.
• Vout: Connected to Vin of the ESP32.

12V Power Supply

• +: Connected to Vin of the 7805 voltage regulator and 12V of the L298N motor driver.
• -: Connected to Gnd of the 7805 voltage regulator and GND of the ESP32.

9V Battery

• +: Connected to 3V3 of the ESP32.
• -: Connected to GND of the ESP32.

Documented Code

ESP32 Code

#define ENA 25
#define IN1 26
#define IN2 27
#define ENB 14
#define IN3 12
#define IN4 13
#define FRONT_IR 32
#define LEFT_IR 35

#define MOTOR_SPEED 150 // Motor speed (range: 0-255)

// Function to move the robot forward
void moveForward() {
  analogWrite(ENA, MOTOR_SPEED);
  analogWrite(ENB, MOTOR_SPEED);
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
}

// Function to turn the robot to the right
void turnRight() {
  analogWrite(ENA, MOTOR_SPEED);
  analogWrite(ENB, MOTOR_SPEED);
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, HIGH);
}

// Function to stop the robot
void stopRobot() {
  analogWrite(ENA, 0);
  analogWrite(ENB, 0);
}

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

  // Set IR sensor pins as inputs
  pinMode(FRONT_IR, INPUT);
  pinMode(LEFT_IR, INPUT);

  // Start serial communication for debugging
  Serial.begin(115200);
}

void loop() {
  // Move the robot forward for 2 seconds
  moveForward();
  delay(2000);

  // Stop the robot for 1 second to read sensor values
  stopRobot();
  delay(1000);

  // Read IR sensor values
  int frontSensor = digitalRead(FRONT_IR);
  int leftSensor = digitalRead(LEFT_IR);

  // Debugging: Print sensor values to the Serial Monitor
  Serial.print("Front IR: ");
  Serial.print(frontSensor);
  Serial.print(" | Left IR: ");
  Serial.println(leftSensor);

  // Decide the next action based on sensor readings
  if (frontSensor == LOW && leftSensor == LOW) {
    // No wall detected; keep moving forward
    moveForward();
  } else {
    // Wall detected; turn right
    turnRight();
    delay(2000); // Allow sufficient time for the turn
  }
}

Additional Code for Second Microcontroller

// Include necessary libraries
#include <Arduino.h>

// Define pin connections
#define IR_LEFT_PIN 34       // IR sensor on the left
#define IR_FRONT_PIN 35      // IR sensor at the front
#define MOTOR_LEFT_ENA 25    // Enable pin for the left motor
#define MOTOR_LEFT_IN1 26    // IN1 pin for the left motor
#define MOTOR_LEFT_IN2 27    // IN2 pin for the left motor
#define MOTOR_RIGHT_ENB