NodeMCU Car MotorShield

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>

String command;             //String to store app command state.
int speedCar = 600;         // 400 - 1023.
int speed_Coeff = 3;

const char* ssid = "NodeMCU Car2";
ESP8266WebServer server(80);

int PWMA = 4; //Right side
int PWMB = 5; //Left side
int DA = 2; //Right reverse
int DB = 0; //Left reverse

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(PWMA, OUTPUT);
  pinMode(PWMB, OUTPUT);
  pinMode(DA, OUTPUT);
  pinMode(DB, OUTPUT);

  // Connecting WiFi

  WiFi.mode(WIFI_AP);
  WiFi.softAP(ssid);

  IPAddress myIP = WiFi.softAPIP();
  Serial.print("AP IP address: ");
  Serial.println(myIP);

  // Starting WEB-server
  server.on ( "/", HTTP_handleRoot );
  server.onNotFound ( HTTP_handleRoot );
  server.begin();
}

void loop() {
  // put your main code here, to run repeatedly:
  server.handleClient();
  command = server.arg("State");

  if (command == "F") goAhead();
  else if (command == "B") goBack();
  else if (command == "L") goLeft();
  else if (command == "R") goRight();
  else if (command == "I") goAheadRight();
  else if (command == "G") goAheadLeft();
  else if (command == "J") goBackRight();
  else if (command == "H") goBackLeft();
  else if (command == "S") stopRobot();
}

void HTTP_handleRoot(void) {

  if ( server.hasArg("State") ) {
    Serial.println(server.arg("State"));
  }
  server.send ( 200, "text/html", "" );
  delay(1);
}

void goLeft() {

  digitalWrite(PWMA, HIGH);
  digitalWrite(DA, LOW);

  digitalWrite(PWMB, HIGH);
  digitalWrite(DB, LOW);
}

void goRight() {

  digitalWrite(PWMA, HIGH);
  digitalWrite(DA, HIGH);

  digitalWrite(PWMB, HIGH);
  digitalWrite(DB, HIGH);
}

void goBack() {
  digitalWrite(PWMA, 450);
  digitalWrite(DA, HIGH);

  digitalWrite(PWMB, 450);
  digitalWrite(DB, LOW);
}

void goAhead() {
  digitalWrite(PWMA, 450);
  digitalWrite(DA, LOW);

  digitalWrite(PWMB, 450);
  digitalWrite(DB, HIGH);

}
void goAheadRight() {
  digitalWrite(PWMA, LOW);
  digitalWrite(DA, LOW);

  digitalWrite(PWMB, HIGH);
  digitalWrite(DB, HIGH);
}

void goAheadLeft() {
  digitalWrite(PWMA, HIGH);
  digitalWrite(DA, LOW);

  digitalWrite(PWMB, LOW);
  digitalWrite(DB, LOW);
}

void goBackRight() {
  digitalWrite(PWMA, LOW);
  digitalWrite(DA, LOW);

  digitalWrite(PWMB, HIGH);
  digitalWrite(DB, LOW);
}

void goBackLeft() {
  digitalWrite(PWMA, HIGH);
  digitalWrite(DA, HIGH);

  digitalWrite(PWMB, LOW);
  digitalWrite(DB, LOW);
}

void stopRobot() {

  digitalWrite(PWMA, LOW);
  digitalWrite(DA, LOW);

  digitalWrite(PWMB, LOW);
  digitalWrite(DB, LOW);
}