[UNO R4 WIFI example] WiFi Web Server LED Blink

< 본 블로그는 ARDUINO docs 을 참고해서 공부하며 작성하였습니다 :-) >

 

⭐ Arduino UNO R4 WiFi

Wi-Fi 네트워크에 연결하고 네트워크 작업을 수행할 수 있는 ESP32-S3 모듈이 내장되어 있음

HTTPS, MQTT, UDP를 포함한 프로토콜이 테스트되고 지원됨

WiFiS3 Arduino UNO R4 Core 와 함께 제공되는 라이브러리

 

⭐ WiFi Web Server LED Blink

🌳 SSID, PASSWORD 로컬 Wi-Fi 네트워크용

네트워크와 비밀번호를 별도의 파일 (헤더) 에 저장하여 정보 보호하기

//arduino_secrets.h header file
#define SECRET_SSID "yournetwork"
#define SECRET_PASS "yourpassword"

 

🌳 UART

UART 통신이란 Serial 통신으로, 데이터 전송 혹은 수신 핀이 하나인 통신

한번에 1byte씩 보내며, 각 bit는 차례(직렬)로 전송

MCU (ex. arduino)에서 많이 쓰이는 방식이며, TX (데이터를 보내는 핀)와 RX (데이터를 받는 핀)이 존재

데이터 수신부과 송신부끼리 TX는 Transmitter(송신부), RX는 Receiver(수신부) 는 교차해서 연결해야 한다.

UART는 Start bit (GND , 0)으로 시작하고, 그 뒤 8개의 Data bit , 그리고 Stop bit (VCC , 1)로 끝난다

따라서 한번에 10개의 bit를 전송하고 받는게 일반적

 

🌳 CODE

/*
  WiFi Web Server LED Blink

  A simple web server that lets you blink an LED via the web.
  This sketch will print the IP address of your WiFi module (once connected)
  to the Serial Monitor. From there, you can open that address in a web browser
  to turn on and off the LED_BUILTIN.

  If the IP address of your board is yourAddress:
  http://yourAddress/H turns the LED on
  http://yourAddress/L turns it off

  This example is written for a network using WPA encryption. For
  WEP or WPA, change the WiFi.begin() call accordingly.

  Circuit:
  * Board with NINA module (Arduino MKR WiFi 1010, MKR VIDOR 4000 and Uno WiFi Rev.2)
  * LED attached to pin 9

  created 25 Nov 2012
  by Tom Igoe

  Find the full UNO R4 WiFi Network documentation here:
  https://docs.arduino.cc/tutorials/uno-r4-wifi/wifi-examples#simple-webserver
 */

#include "WiFiS3.h"

//#include "arduino_secrets.h" 

#define SECRET_SSID "class924"
#define SECRET_PASS "kosta90009"
///////please enter your sensitive data in the Secret tab/arduino_secrets.h
char ssid[] = SECRET_SSID;        // your network SSID (name)
char pass[] = SECRET_PASS;    // your network password (use for WPA, or use as key for WEP)
int keyIndex = 0;                 // your network key index number (needed only for WEP)

int led =  LED_BUILTIN;
int status = WL_IDLE_STATUS;
WiFiServer server(80);

void setup() {
  Serial.begin(9600);      // initialize serial communication
  pinMode(led, OUTPUT);      // set the LED pin mode

  // check for the WiFi module:
  if (WiFi.status() == WL_NO_MODULE) {
    Serial.println("Communication with WiFi module failed!");
    // don't continue
    while (true);
  }

  // WiFi.firmwareVersion() : 모듈에서 실행 중인 펌웨어 버전을 문자열로 반환
  String fv = WiFi.firmwareVersion();
  if (fv < WIFI_FIRMWARE_LATEST_VERSION) {
    Serial.println("Please upgrade the firmware");
  }

  // attempt to connect to WiFi network:
  while (status != WL_CONNECTED) {
    Serial.print("Attempting to connect to Network named: ");
    Serial.println(ssid);                   // print the network name (SSID);

    // Connect to WPA/WPA2 network. Change this line if using open or WEP network:
    status = WiFi.begin(ssid, pass);
    // wait 10 seconds for connection:
    delay(5000);
  }

// by default the local IP address
  // you can override it with the following:
  // 고정 IP 주소를 구성, WiFi 쉴드의 DNS, 게이트웨이 및 서브넷 주소를 변경
  // WiFi.config(IPAddress(192,168,0,34));

  server.begin();                           // start the web server on port 80
  printWifiStatus();                        // you're connected now, so print out the status
}


void loop() {
  WiFiClient client = server.available();   // listen for incoming clients

  if (client) {                             // if you get a client,
    Serial.println("new client");           // print a message out the serial port
    String currentLine = "";                // make a String to hold incoming data from the client
    while (client.connected()) {            // loop while the client's connected
      if (client.available()) {             // if there's bytes to read from the client,
        char c = client.read();             // read a byte, then
        Serial.write(c);                    // print it out to the serial monitor
        if (c == '\n') {                    // if the byte is a newline character

          // if the current line is blank, you got two newline characters in a row.
          // that's the end of the client HTTP request, so send a response:
          if (currentLine.length() == 0) {
            // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
            // and a content-type so the client knows what's coming, then a blank line:
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println();

            // the content of the HTTP response follows the header:
            client.print("<p style=\"font-size:7vw;\">Click <a href=\"/H\">here</a> turn the LED on<br></p>");
            client.print("<p style=\"font-size:7vw;\">Click <a href=\"/L\">here</a> turn the LED off<br></p>");
            
            // The HTTP response ends with another blank line:
            client.println();
            // break out of the while loop:
            break;
          } else {    // if you got a newline, then clear currentLine:
            currentLine = "";
          }
        } else if (c != '\r') {  // if you got anything else but a carriage return character,
          currentLine += c;      // add it to the end of the currentLine
        }

        // Check to see if the client request was "GET /H" or "GET /L":
        if (currentLine.endsWith("GET /H")) {
          digitalWrite(LED_BUILTIN, HIGH);               // GET /H turns the LED on
        }
        if (currentLine.endsWith("GET /L")) {
          digitalWrite(LED_BUILTIN, LOW);                // GET /L turns the LED off
        }
      }
      
    }
    // close the connection:
    client.stop();
    Serial.println("client disconnected");
  }
}

void printWifiStatus() {
  // print the SSID of the network you're attached to:
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());

  // print your board's IP address:
  // WiFi.localIP() : WiFi 쉴드의 IP 주소
  IPAddress ip = WiFi.localIP();
  Serial.print("IP Address: ");
  Serial.println(ip);

  // print the received signal strength:
  long rssi = WiFi.RSSI();
  Serial.print("signal strength (RSSI):");
  Serial.print(rssi);
  Serial.println(" dBm");
  // print where to go in a browser:
  Serial.print("To see this page in action, open a browser to http://");
  Serial.println(ip);
}