Robot Motion: DC Motors, Driver Wiring (L298N vs TB6612 vs DRV8833) & Locomotion

         + V_BAT (Battery Positive)
             │                │
          [ Q1 ]            [ Q2 ]
             │──[ Motor M ]───│
          [ Q3 ]            [ Q4 ]
             │                │
            GND              GND

• Forward Drive:  Q1 & Q4 closed -> Current flows LEFT to RIGHT
• Reverse Drive:  Q2 & Q3 closed -> Current flows RIGHT to LEFT
• Active Brake:   Q3 & Q4 closed (or Q1 & Q2) -> Shorts motor terminals
• Coast/Freewheel: All switches open -> Motor spins down freely

// Pin Assignments for Left and Right Motors
const int ENA = 5;  // Left Motor Speed (PWM)
const int IN1 = 7;  // Left Motor Direction A
const int IN2 = 8;  // Left Motor Direction B

const int ENB = 6;  // Right Motor Speed (PWM)
const int IN3 = 9;  // Right Motor Direction A
const int IN4 = 10; // Right Motor Direction B

void setup() {
  pinMode(ENA, OUTPUT);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  
  pinMode(ENB, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
}

void setMotors(int leftSpeed, int rightSpeed) {
  // Left Motor Direction & Speed
  if (leftSpeed >= 0) {
    digitalWrite(IN1, HIGH);
    digitalWrite(IN2, LOW);
    analogWrite(ENA, constrain(leftSpeed, 0, 255));
  } else {
    digitalWrite(IN1, LOW);
    digitalWrite(IN2, HIGH);
    analogWrite(ENA, constrain(-leftSpeed, 0, 255));
  }

  // Right Motor Direction & Speed
  if (rightSpeed >= 0) {
    digitalWrite(IN3, HIGH);
    digitalWrite(IN4, LOW);
    analogWrite(ENB, constrain(rightSpeed, 0, 255));
  } else {
    digitalWrite(IN3, LOW);
    digitalWrite(IN4, HIGH);
    analogWrite(ENB, constrain(-rightSpeed, 0, 255));
  }
}

void brake() {
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, LOW);
  analogWrite(ENA, 0);
  analogWrite(ENB, 0);
}

void loop() {
  setMotors(200, 200);   // Move Forward at ~80% speed
  delay(2000);

  setMotors(-180, 180);  // Spin Turn Left on the spot
  delay(800);

  setMotors(200, 200);   // Move Forward
  delay(2000);

  brake();               // Active Stop
  delay(3000);
}