// Arduino UNO code
/*
 * This Arduino Sketch receives commands from the ESP8266 ESP-01 module via
 * UART and controls the H-bridge and motors accordingly.
 */

// Pin definitions
const int trigPin = 6;
const int echoPin = 7;
const int motorA1 = 9;
const int motorA2 = 8;
const int motorB1 = 5;
const int motorB2 = 4;
const int enableA = 10;
const int enableB = 3;

void setup() {
  // Initialize serial communication
  Serial.begin(115200);

  // Initialize pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(motorA1, OUTPUT);
  pinMode(motorA2, OUTPUT);
  pinMode(motorB1, OUTPUT);
  pinMode(motorB2, OUTPUT);
  pinMode(enableA, OUTPUT);
  pinMode(enableB, OUTPUT);

  // Enable motors
  analogWrite(enableA, 255);
  analogWrite(enableB, 255);
}

void loop() {
  if (Serial.available() > 0) {
    String command = Serial.readStringUntil('\n');
    command.trim();
    if (command == "forward") {
      moveForward();
    } else if (command == "backward") {
      moveBackward();
    } else if (command == "left") {
      turnLeft();
    } else if (command == "right") {
      turnRight();
    } else if (command == "stop") {
      stopMotors();
    }
  }
}

// Motor control functions
void moveForward() {
  digitalWrite(motorA1, HIGH);
  digitalWrite(motorA2, LOW);
  digitalWrite(motorB1, HIGH);
  digitalWrite(motorB2, LOW);
}

void moveBackward() {
  digitalWrite(motorA1, LOW);
  digitalWrite(motorA2, HIGH);
  digitalWrite(motorB1, LOW);
  digitalWrite(motorB2, HIGH);
}

void turnRight() {
  digitalWrite(motorA1, LOW);
  digitalWrite(motorA2, HIGH);
  digitalWrite(motorB1, HIGH);
  digitalWrite(motorB2, LOW);
}

void turnLeft() {
  digitalWrite(motorA1, HIGH);
  digitalWrite(motorA2, LOW);
  digitalWrite(motorB1, LOW);
  digitalWrite(motorB2, HIGH);
}

void stopMotors() {
  digitalWrite(motorA1, LOW);
  digitalWrite(motorA2, LOW);
  digitalWrite(motorB1, LOW);
  digitalWrite(motorB2, LOW);
}