ESP with Serial monitor controlling and sending 0/1

ESP2.ino

#include <ESP8266WiFi.h>        // Include the Wi-Fi library
#include <WiFiUdp.h>

const char *ssid = "ESP8266"; // The name of the Wi-Fi network that will be created
const char *password = "00000000";   // The password required to connect to it, leave blank for an open network

WiFiUDP Udp;
unsigned int localUdpPort = 4210;  // local port to listen on
char incomingPacket[255];  // buffer for incoming packets
char  replyPacket[] = "Hi there! Got the message :-)";  // a reply string to send back


void setup() {
  Serial.begin(115200);
  delay(10);
  Serial.println('\n');

  WiFi.begin(ssid, password);             // Connect to the network
  Serial.print("Connecting to ");
  Serial.print(ssid); Serial.println(" ...");

  int i = 0;
  while (WiFi.status() != WL_CONNECTED) { // Wait for the Wi-Fi to connect
    delay(1000);
    Serial.print(++i); Serial.print(' ');
  }

  Serial.println('\n');
  Serial.println("Connection established!");  
  Serial.print("IP address:\t");
  Serial.println(WiFi.localIP());         // Send the IP address of the ESP8266 to the computer

  Udp.begin(localUdpPort);
  Serial.printf("Now listening at IP %s, UDP port %d\n", WiFi.localIP().toString().c_str(), localUdpPort);
  Udp.beginPacket("192.168.4.1", 4210);
  Udp.write("Initial msg");
  Udp.endPacket();
  


}

void loop() {
  int packetSize = Udp.parsePacket();
  if(Serial.available())
  {
    char x = Serial.read();
    Udp.beginPacket("192.168.4.1", 4210);
    Udp.write(x);
    Serial.print("Writing ");
    Serial.println(x);
    Udp.endPacket(); 
  }
  delay(100);
 }