NodeMCU Car with L298N

#define ENA   D1          // Enable/speed motors Right        GPIO14(D1)
#define IN_1  D2          // L298N in1 motors Rightx          GPIO15(D2)
#define IN_2  D3          // L298N in2 motors Right           GPIO13(D3)
#define IN_3  D4           // L298N in3 motors Left            GPIO2(D4)
#define IN_4  D5           // L298N in4 motors Left            GPIO0(D5)
#define ENB   D6          // Enable/speed motors Left         GPIO12(D6)


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

String command;             //String to store app command state.
int speedCar = 800;         // 400 - 1023.
int speed_Coeff = 3;

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

void setup() {

 pinMode(ENA, OUTPUT);
 pinMode(ENB, OUTPUT);
 pinMode(IN_1, OUTPUT);
 pinMode(IN_2, OUTPUT);
 pinMode(IN_3, OUTPUT);
 pinMode(IN_4, OUTPUT);

  Serial.begin(115200);

// 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 goAhead(){

      digitalWrite(IN_1, LOW);
      digitalWrite(IN_2, HIGH);
      analogWrite(ENA, speedCar);

      digitalWrite(IN_3, LOW);
      digitalWrite(IN_4, HIGH);
      analogWrite(ENB, speedCar);
  }

void goBack(){

      digitalWrite(IN_1, HIGH);
      digitalWrite(IN_2, LOW);
      analogWrite(ENA, speedCar);

      digitalWrite(IN_3, HIGH);
      digitalWrite(IN_4, LOW);
      analogWrite(ENB, speedCar);
  }

void goRight(){

      digitalWrite(IN_1, HIGH);
      digitalWrite(IN_2, LOW);
      analogWrite(ENA, speedCar);

      digitalWrite(IN_3, LOW);
      digitalWrite(IN_4, HIGH);
      analogWrite(ENB, speedCar);
  }

void goLeft(){

      digitalWrite(IN_1, LOW);
      digitalWrite(IN_2, HIGH);
      analogWrite(ENA, speedCar);

      digitalWrite(IN_3, HIGH);
      digitalWrite(IN_4, LOW);
      analogWrite(ENB, speedCar);
  }

void goAheadRight(){

      digitalWrite(IN_1, LOW);
      digitalWrite(IN_2, HIGH);
      analogWrite(ENA, speedCar/speed_Coeff);

      digitalWrite(IN_3, LOW);
      digitalWrite(IN_4, HIGH);
      analogWrite(ENB, speedCar);
   }

void goAheadLeft(){

      digitalWrite(IN_1, LOW);
      digitalWrite(IN_2, HIGH);
      analogWrite(ENA, speedCar);

      digitalWrite(IN_3, LOW);
      digitalWrite(IN_4, HIGH);
      analogWrite(ENB, speedCar/speed_Coeff);
  }

void goBackRight(){

      digitalWrite(IN_1, HIGH);
      digitalWrite(IN_2, LOW);
      analogWrite(ENA, speedCar/speed_Coeff);

      digitalWrite(IN_3, HIGH);
      digitalWrite(IN_4, LOW);
      analogWrite(ENB, speedCar);
  }

void goBackLeft(){

      digitalWrite(IN_1, HIGH);
      digitalWrite(IN_2, LOW);
      analogWrite(ENA, speedCar);

      digitalWrite(IN_3, HIGH);
      digitalWrite(IN_4, LOW);
      analogWrite(ENB, speedCar/speed_Coeff);
  }

void stopRobot(){

      digitalWrite(IN_1, LOW);
      digitalWrite(IN_2, LOW);
      analogWrite(ENA, speedCar);

      digitalWrite(IN_3, LOW);
      digitalWrite(IN_4, LOW);
      analogWrite(ENB, speedCar);
 }

void loop() {
    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 == "0") speedCar = 400;
      else if (command == "1") speedCar = 470;
      else if (command == "2") speedCar = 540;
      else if (command == "3") speedCar = 610;
      else if (command == "4") speedCar = 680;
      else if (command == "5") speedCar = 750;
      else if (command == "6") speedCar = 820;
      else if (command == "7") speedCar = 890;
      else if (command == "8") speedCar = 960;
      else if (command == "9") speedCar = 1023;
      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);
}