ESP8266 Community Forum

Dear all,
I have some questions:
1. When I load program for ESP8266 (use web turn ON/OFF LED on ESP8266) then OK. But I can't use AT command to commmunication ESP8266 with my computer. Why?
This is code program (below)
2. I need to make a project use STM32F103 communication ESP8266. Computer use Visual Studio Code (C#). How do?
Thanks so much,

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WiFiMulti.h>
#include <ESP8266mDNS.h>
#include <ESP8266WebServer.h>

ESP8266WiFiMulti wifiMulti; // Create an instance of the ESP8266WiFiMulti class, called 'wifiMulti'

ESP8266WebServer server(80); // Create a webserver object that listens for HTTP request on port 80

const int led = 2;

void handleRoot(); // function prototypes for HTTP handlers
void handleLED();
void handleNotFound();

void setup(void){
Serial.begin(115200); // Start the Serial communication to send messages to the computer
delay(10);
Serial.println('\n');

pinMode(led, OUTPUT);

wifiMulti.addAP("COSMOS-X2", "123456cm5"); // add Wi-Fi networks you want to connect to
wifiMulti.addAP("ssid_from_AP_2", "your_password_for_AP_2");
wifiMulti.addAP("ssid_from_AP_3", "your_password_for_AP_3");

Serial.println("Connecting ...");
int i = 0;
while (wifiMulti.run() != WL_CONNECTED) { // Wait for the Wi-Fi to connect: scan for Wi-Fi networks, and connect to the strongest of the networks above
delay(250);
Serial.print('.');
}
Serial.println('\n');
Serial.print("Connected to ");
Serial.println(WiFi.SSID()); // Tell us what network we're connected to
Serial.print("IP address:\t");
Serial.println(WiFi.localIP()); // Send the IP address of the ESP8266 to the computer

if (MDNS.begin("esp8266")) { // Start the mDNS responder for esp8266.local
Serial.println("mDNS responder started");
} else {
Serial.println("Error setting up MDNS responder!");
}

server.on("/", HTTP_GET, handleRoot); // Call the 'handleRoot' function when a client requests URI "/"
server.on("/LED", HTTP_POST, handleLED); // Call the 'handleLED' function when a POST request is made to URI "/LED"
server.onNotFound(handleNotFound); // When a client requests an unknown URI (i.e. something other than "/"), call function "handleNotFound"

server.begin(); // Actually start the server
Serial.println("HTTP server started");
}

void loop(void){
server.handleClient(); // Listen for HTTP requests from clients
}

void handleRoot() { // When URI / is requested, send a web page with a button to toggle the LED
server.send(200, "text/html", "<form action=\"/LED\" method=\"POST\"><input type=\"submit\" value=\"Toggle LED\"></form>");
}

void handleLED() { // If a POST request is made to URI /LED
digitalWrite(led,!digitalRead(led)); // Change the state of the LED
server.sendHeader("Location","/"); // Add a header to respond with a new location for the browser to go to the home page again
server.send(303); // Send it back to the browser with an HTTP status 303 (See Other) to redirect
}

void handleNotFound(){
server.send(404, "text/plain", "404: Not found"); // Send HTTP status 404 (Not Found) when there's no handler for the URI in the request
}