PlayStation-Controlled Blinking Rover

#include <Arduino.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <PS4Controller.h>

constexpr int LEFT_IN1 = 13;
constexpr int LEFT_IN2 = 14;
constexpr int RIGHT_IN1 = 27;
constexpr int RIGHT_IN2 = 32;
constexpr int LEFT_EN = 25;
constexpr int RIGHT_EN = 26;
constexpr int OLED_SDA = 21;
constexpr int OLED_SCL = 22;

constexpr uint8_t SCREEN_WIDTH = 128;
constexpr uint8_t SCREEN_HEIGHT = 64;
constexpr int JOYSTICK_DEAD_ZONE = 28;

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

bool eyesClosed = false;
unsigned long blinkStartedAt = 0;
unsigned long nextBlinkAt = 0;

void setMotorPins(int pinA, int pinB, int direction) {
  if (direction > 0) {
    digitalWrite(pinA, HIGH);
    digitalWrite(pinB, LOW);
  } else if (direction < 0) {
    digitalWrite(pinA, LOW);
    digitalWrite(pinB, HIGH);
  } else {
    digitalWrite(pinA, LOW);
    digitalWrite(pinB, LOW);
  }
}

void stopRover() {
  setMotorPins(LEFT_IN1, LEFT_IN2, 0);
  setMotorPins(RIGHT_IN1, RIGHT_IN2, 0);
}

void drawEyes(bool closed) {
  display.clearDisplay();
  if (closed) {
    display.drawLine(24, 32, 52, 32, SSD1306_WHITE);
    display.drawLine(76, 32, 104, 32, SSD1306_WHITE);
  } else {
    display.fillRoundRect(24, 17, 28, 32, 12, SSD1306_WHITE);
    display.fillRoundRect(76, 17, 28, 32, 12, SSD1306_WHITE);
    display.fillCircle(42, 33, 7, SSD1306_BLACK);
    display.fillCircle(94, 33, 7, SSD1306_BLACK);
  }
  display.display();
}

void updateBlink() {
  const unsigned long now = millis();
  if (!eyesClosed && now >= nextBlinkAt) {
    eyesClosed = true;
    blinkStartedAt = now;
    drawEyes(true);
  } else if (eyesClosed && now - blinkStartedAt >= 150) {
    eyesClosed = false;
    nextBlinkAt = now + random(2500, 6000);
    drawEyes(false);
  }
}

int applyDeadZone(int value) {
  return abs(value) < JOYSTICK_DEAD_ZONE ? 0 : value;
}

void driveFromController() {
  const int throttle = -applyDeadZone(PS4.LStickY());
  const int steer = applyDeadZone(PS4.LStickX());

  if (throttle == 0 && steer == 0) {
    stopRover();
    return;
  }

  int leftCommand = throttle + steer;
  int rightCommand = throttle - steer;
  leftCommand = constrain(leftCommand, -127, 127);
  rightCommand = constrain(rightCommand, -127, 127);

  setMotorPins(LEFT_IN1, LEFT_IN2, (leftCommand > 0) - (leftCommand < 0));
  setMotorPins(RIGHT_IN1, RIGHT_IN2, (rightCommand > 0) - (rightCommand < 0));
}

void setup() {
  Serial.begin(115200);
  randomSeed(esp_random());

  pinMode(LEFT_IN1, OUTPUT);
  pinMode(LEFT_IN2, OUTPUT);
  pinMode(RIGHT_IN1, OUTPUT);
  pinMode(RIGHT_IN2, OUTPUT);
  pinMode(LEFT_EN, OUTPUT);
  pinMode(RIGHT_EN, OUTPUT);
  digitalWrite(LEFT_EN, HIGH);
  digitalWrite(RIGHT_EN, HIGH);
  stopRover();

  Wire.begin(OLED_SDA, OLED_SCL);
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("OLED was not found at address 0x3C.");
    while (true) {
      delay(1000);
    }
  }
  drawEyes(false);
  nextBlinkAt = millis() + random(2500, 6000);

  // The paired PlayStation controller provides the rover's left-stick commands.
  PS4.begin();
  Serial.println("Rover ready. Pair the PS4 controller, then use its left stick to drive.");
}

void loop() {
  updateBlink();

  if (PS4.isConnected()) {
    driveFromController();
  } else {
    stopRover();
  }

  delay(10);
}