Circuit Documentation

Summary

This circuit is designed to control a mobile robot equipped with DC motors, ultrasonic sensors, and infrared sensors. The Arduino UNO serves as the central microcontroller, interfacing with an HC-SR04 Ultrasonic Sensor for distance measurement, two IR sensors for line tracking, and an L298N DC motor driver to control the gearmotors attached to the robot's wheels. A rocker switch is used to control the power supply to the motor driver. The circuit is powered by a 7.4V battery.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• Used for controlling the sensors and motor driver
• Provides digital and analog I/O pins

HC-SR04 Ultrasonic Sensor

• Ultrasonic distance sensor
• Measures the distance to obstacles in front of the sensor

Gearmotor DC Wheels (Left and Right)

• DC motors with gear reduction
• Provide movement to the robot's wheels

L298N DC Motor Driver

• Dual H-bridge motor driver
• Controls the direction and speed of the DC motors

Rocker Switch (SPST)

• Single Pole Single Throw switch
• Used to control the power supply to the motor driver

IR Sensors

• Infrared sensors for line tracking
• Detects the presence of a line under the robot

7.4V Battery

• Power source for the circuit
• Supplies power to the motor driver and Arduino UNO

Wiring Details

Arduino UNO

• 5V connected to the VCC of HC-SR04 Ultrasonic Sensor and IR sensors
• GND connected to the GND of HC-SR04 Ultrasonic Sensor, IR sensors, and L298N DC motor driver
• Vin connected to the 5V input of the L298N DC motor driver
• A0 connected to the output of the right IR sensor
• A1 connected to the output of the left IR sensor
• A2 connected to the ECHO pin of the HC-SR04 Ultrasonic Sensor
• A3 connected to the TRIG pin of the HC-SR04 Ultrasonic Sensor
• D5 connected to the ENB pin of the L298N DC motor driver
• D6 connected to the IN4 pin of the L298N DC motor driver
• D7 connected to the IN3 pin of the L298N DC motor driver
• D8 connected to the IN2 pin of the L298N DC motor driver
• D9 connected to the IN1 pin of the L298N DC motor driver
• D10 connected to the ENA pin of the L298N DC motor driver

HC-SR04 Ultrasonic Sensor

• VCC connected to the 5V of Arduino UNO
• GND connected to the GND of Arduino UNO
• ECHO connected to the A2 pin of Arduino UNO
• TRIG connected to the A3 pin of Arduino UNO

Gearmotor DC Wheels (Left)

• PIN1 connected to the OUT4 pin of the L298N DC motor driver
• PIN2 connected to the OUT3 pin of the L298N DC motor driver

Gearmotor DC Wheels (Right)

• PIN1 connected to the OUT2 pin of the L298N DC motor driver
• PIN2 connected to the OUT1 pin of the L298N DC motor driver

L298N DC Motor Driver

• GND connected to the GND of Arduino UNO and the negative terminal of the 7.4V battery
• 5V connected to the Vin pin of Arduino UNO
• 12V connected to the terminal 2 of the Rocker Switch (SPST)
• ENA, IN1, IN2, IN3, IN4, ENB connected to the respective pins on the Arduino UNO as detailed above
• OUT1, OUT2, OUT3, OUT4 connected to the respective pins on the Gearmotor DC Wheels

Rocker Switch (SPST)

• Terminal 1 connected to the positive terminal of the 7.4V battery
• Terminal 2 connected to the 12V input of the L298N DC motor driver

IR Sensors

• out connected to the A0 and A1 pins of Arduino UNO for the right and left sensors, respectively
• gnd connected to the GND of Arduino UNO
• vcc connected to the 5V of Arduino UNO

7.4V Battery

• + connected to terminal 1 of the Rocker Switch (SPST)
• - connected to the GND of the L298N DC motor driver

Documented Code

// Declaration of pins for sensors, motors, and the ultrasonic sensor

const int IRDroit = A0;                
const int IRGauche = A1;
              
const int brocheEcho = A2;  
const int TrigUltra = A3; 
           
const int enableMoteurGauche = 5;              
const int moteurGauchePin1 = 6;   // Forward direction     
const int moteurGauchePin2 = 7;   // Reverse direction
const int enableMoteurDroit = 10;        
const int moteurDroitPin1 = 9;    // Forward direction     
const int moteurDroitPin2 = 8;     // Reverse direction          

void setup() {
  pinMode(TrigUltra, OUTPUT);
  pinMode(brocheEcho, INPUT);
  pinMode(IRDroit, INPUT);
  pinMode(IRGauche, INPUT);

  pinMode(moteurGauchePin1, OUTPUT);
  pinMode(moteurGauchePin2, OUTPUT);
  pinMode(moteurDroitPin1, OUTPUT);
  pinMode(moteurDroitPin2, OUTPUT);

  pinMode(enableMoteurGauche, OUTPUT);
  pinMode(enableMoteurDroit, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  suivreLigneHauteVitesse();

  long distance = lireDistanceUltrason();
  
  if (distance < 20) {
    approcherEtPousserBalle();
  }
}

void suivreLigneHauteVitesse() {

  bool irDroit = digitalRead(IRDroit);    
  bool irGauche = digitalRead(IRGauche);  

  if (irDroit == HIGH && irGauche == HIGH) {
    avancer(255); 
  } else if (irDroit == HIGH && irGauche == LOW) {
    tournerGauche(150);    
  } else if (irDroit == LOW && irGauche == HIGH) {
    tournerDroite(150);   
  } else {
    arreter();          
  }
}

// Function to approach and push the ball into the hole
void approcherEtPousserBalle() {
  long distance = lireDistanceUltrason();

  while (distance > 2) {
    distance = lireDistanceUltrason();
    int vitesse = map(distance, 2, 20, 100, 200); // Gradually slow down
    avancer(vitesse);
    delay(15);
  }

  // Check if the ball is in the hole
  long distancePrecedente = distance;
  distance = lireDistanceUltrason();

  if (distance - distancePrecedente > 10) {
    arreter();
  } else {
    avancer(100);
  }
}

// Function to read the distance with the ultrasonic sensor
long lireDistanceUltrason() {
  digitalWrite(TrigUltra, LOW);
  delayMicroseconds(2);
  digitalWrite(TrigUltra, HIGH);
  delayMicroseconds(10);
  digitalWrite(TrigUltra, LOW);

  long duree = pulseIn(brocheEcho, HIGH);
  long distance = duree * 0.0344 / 2;
  return distance;
}

// Functions to control the motors

void avancer(int vitesse) {
  analogWrite(enableMoteurGauche, vitesse);
  analogWrite(enableMoteurDroit, vitesse);
  digitalWrite(moteurGauchePin1, HIGH);
  digitalWrite(moteurGauchePin2, LOW);
  digitalWrite(moteurDroitPin1, HIGH);
  digitalWrite(moteurDroitPin2, LOW);
}

void tournerGauche(int vitesse) {
  analogWrite(enableMoteurGauche, vitesse);
  analogWrite(enableMoteurDroit, vitesse);
  digitalWrite(moteurGauchePin1, LOW);
  digitalWrite(moteurGauchePin2, HIGH);
  digitalWrite(moteurDroitPin1, HIGH);
  digitalWrite(moteurDroitPin2, LOW);
}

void tournerDroite(int vitesse) {
  analogWrite(enableMoteurGauche, vitesse);
  analogWrite(enableMoteurDroit, vitesse);
  digitalWrite(moteurGauchePin1, HIGH);
  digitalWrite(moteurGauchePin2, LOW);
  digitalWrite(moteurDroitPin1, LOW);
  digitalWrite(moteurDroitPin2, HIGH);