Two drivers, one motor

/*
  11 — Two drivers, one motor
  Board: ESP32.  Parts: DC motor, L293D module, L9110 module.

  Same motor, two drivers, to see why there is more than one.
    L9110: two pins per motor, PWM on one of them.
    L293D module: direction on IN1/IN2, speed on a separate ENABLE pin. It supports a
           wider motor-supply voltage range and separate enable control, while the L9110
           module is simpler for small low-voltage motors like the one in this kit.
  Both modules include motor-protection circuitry. A motor straight on a GPIO
  can damage the board.

  Wiring (move the motor between the two — only one driver at a time):
    L9110:  VCC -> VIN (5 V), GND -> GND, A-1A -> GPIO 16, A-1B -> GPIO 17, motor -> MOTOR A
    L293D:  VCC/+5 -> VIN, motor supply (VS / +12V terminal) -> VIN for this small motor,
            GND -> GND, IN1 -> GPIO 25, IN2 -> GPIO 33, ENA -> GPIO 32, motor -> OUT1/OUT2
            (some modules have ENA jumpered permanently HIGH — then remove the
             jumper to control speed, or leave it and the ENA line does nothing)
  Set DRIVER below to match where the motor is plugged in.
*/

#define DRIVER_L9110 1
#define DRIVER_L293D 2
#define DRIVER DRIVER_L9110        // <-- change to DRIVER_L293D for the second half

const int L9110_A1A = 16, L9110_A1B = 17;
const int L293D_IN1 = 25, L293D_IN2 = 33, L293D_ENA = 32;

void driveL9110(int speed) {              // speed -255..255
  if (speed >= 0) { analogWrite(L9110_A1A, speed);  digitalWrite(L9110_A1B, LOW); }
  else            { digitalWrite(L9110_A1A, LOW);   analogWrite(L9110_A1B, -speed); }
}

void driveL293D(int speed) {              // direction on IN1/IN2, magnitude on ENA
  digitalWrite(L293D_IN1, speed >= 0 ? HIGH : LOW);
  digitalWrite(L293D_IN2, speed >= 0 ? LOW  : HIGH);
  analogWrite(L293D_ENA, abs(speed));
}

void drive(int speed) {
#if DRIVER == DRIVER_L9110
  driveL9110(speed);
#else
  driveL293D(speed);
#endif
}

void setup() {
  Serial.begin(115200);
  const int pins[] = {L9110_A1A, L9110_A1B, L293D_IN1, L293D_IN2, L293D_ENA};
  for (int p : pins) { pinMode(p, OUTPUT); digitalWrite(p, LOW); }
  Serial.println(DRIVER == DRIVER_L9110 ? "Driver: L9110" : "Driver: L293D");
}

void loop() {
  // Ramp forward, pause, ramp backward, pause — the same pattern on either driver.
  for (int s = 70;  s <= 255; s += 5) { drive(s);  delay(30); }
  delay(800);
  drive(0); delay(500);
  for (int s = -70; s >= -255; s -= 5) { drive(s); delay(30); }
  delay(800);
  drive(0); delay(1500);
}