tcp/tcp_server/tcp_server.ino

#include <WiFi.h>
#include <WiFiClient.h>
#include <WiFiAP.h>
#define PORT 9100
void SerialRe(void);
uint8_t buffer[512];
const char* ssid     = "yourssid";
const char* password = "12345678";
WiFiServer server(PORT);
WiFiClient client;
IPAddress myIP;
void setup() {
    Serial.begin(921600);
    Serial.setTimeout(1);
    Serial.setRxBufferSize(512);
    Serial.onReceive(SerialRe,true);

    Serial.println();
    Serial.println("Configuring access point...");
    // You can remove the password parameter if you want the AP to be open.
    WiFi.softAP(ssid, password);
    myIP = WiFi.softAPIP();
    Serial.println("AP IP address: ");
    Serial.println(myIP);
    server.begin();
}
void loop() {
  if(!client.connected()){
    myIP = WiFi.softAPIP();
    Serial.println("AP IP address: ");
    Serial.println(myIP);
    client = server.available();     
  }
   delay(1000); 
}
void SerialRe(){
  while(Serial.available()>0){
    int cnt=Serial.available(); 
    if(cnt<=512){
      Serial.readBytes(buffer,cnt);
      if(client) client.write(buffer,cnt);
    }else {
      Serial.readBytes(buffer,512);
      if(client) client.write(buffer,512);
    }
  }  
}