#define ENA   14          // Enable/speed motors Right        GPIO14(D5)
#define ENB   12          // Enable/speed motors Left         GPIO12(D6)
#define IN_1  15          // L298N in1 motors Right           GPIO15(D8)
#define IN_2  13          // L298N in2 motors Right           GPIO13(D7)
#define IN_3  2           // L298N in3 motors Left            GPIO2(D4)
#define IN_4  0           // L298N in4 motors Left            GPIO0(D3)

#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);

}