網頁控制LED燈-ESP32

tags: `esp32`

先上程式碼

#include <WiFi.h>

const char* ssid="基地台名稱";
const char* password="基地台密碼";

WiFiServer server(80);

String header;

String output2="off";
const int output=2;
unsigned long currentTime=millis();
unsigned long previousTime=0;
void setup(){
  pinMode(output, OUTPUT);
  digitalWrite(output, LOW);
  WiFi.begin(ssid, password);
  Serial.begin(115200);
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println("已連線到基地台");
  Serial.print("基地台名稱: ");
  Serial.println(ssid);
  Serial.println(WiFi.localIP());
  server.begin();
}

void loop(){
  WiFiClient client=server.available();
  if (client){
    currentTime=millis();
    previousTime=currentTime;
    Serial.println("新的客戶端");
    String currentLine="";
    while (client.connected()&&currentTime-previousTime<=2000)
    {
      currentTime=millis();
      if (client.available()){
        char c=client.read();
        Serial.write(c);
        header+=c;
        if (c=='\n'){
          if (currentLine.length()==0){
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println("Connection: close");
            client.println();
            if (header.indexOf("GET /2/on")>=0){
              Serial.println("on");
              output2="on";
              digitalWrite(output, HIGH);
            }else if (header.indexOf("GET /2/off")>=0){
              Serial.println("off");
              output2="off";
              digitalWrite(output, LOW);
            }
            client.println("<!DOCTYPE html><html>");
            client.println("<style>html {text-align: center;font-family: Arial;display: inline-block;margin: auto;}");
            client.println(".button {background-color: #e0e252; border: none;color: white;padding: 15px 35px;");
            client.println("text-align: center;text-decoration: none;display: inline-block;font-size: 16px;}");
            client.println(".button2 {background-color: #b0b1a2;padding: 15px 32px;}</style></head>");
            
            client.println("<body><h1>ESP32 Web Server</h1>");
            
            client.println("<p>GPIO-2  "+output2+"</p>");
               
            if (output2=="off") {
              client.println("<p><a href=\"/2/on\"><button class=\"button\">ON</button></a></p>");
              client.println("<p><a href=\"/2/off\"><button class=\"button button2\">OFF</button></a></p>");
            } else if (output2=="on"){
              client.println("<p><a href=\"/2/on\"><button class=\"button button2\">ON</button></a></p>");
              client.println("<p><a href=\"/2/off\"><button class=\"button\">OFF</button></a></p>");
            }
            client.println("</body></html>");
            client.println();
            break;
          }else{
            currentLine="";
          }
        }
      }
    }
  header="";
  client.stop();
  Serial.println("Client disconnected.");
  Serial.println("");
  }
}

解析

匯入WIFI的庫

#include <WiFi.h>

定義基地台名稱和密碼

const char* ssid="基地台名稱";
const char* password="基地台密碼";

定義伺服器的端口

WiFiServer server(80);

建立存放接數到的檔頭

String header;

網址列預設內建LED為off
例如:http://localhost/off

String output2="off";

建立LED腳位,紀錄當下時間,和過去的時間

const int output=2;
unsigned long currentTime=millis();
unsigned long previousTime=0;

主要是建立WiFi連線到基地台的初始化
包含伺服端的初始化,如果連線成功後,
會在監控視窗上顯示IP

void setup(){
  pinMode(output, OUTPUT);
  digitalWrite(output, LOW);
  WiFi.begin(ssid, password);
  Serial.begin(115200);
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println("已連線到基地台");
  Serial.print("基地台名稱: ");
  Serial.println(ssid);
  Serial.println(WiFi.localIP());
  server.begin();
}

在void loop(){}裡面
先建立客服端的監聽

WiFiClient client=server.available();

如果客戶端和伺服端能成功建立溝通,伺服端會一直監聽客服端所給予的請求
這個請求是以字串被存入變數並存放於內,如果得到on就回應開燈,女果得到off
就關燈

if (client){
    currentTime=millis();
    previousTime=currentTime;
    Serial.println("新的客戶端");
    String currentLine="";
    while (client.connected()&&currentTime-previousTime<=2000)
    {
      currentTime=millis();
      if (client.available()){
        char c=client.read();
        Serial.write(c);
        header+=c;
        if (c=='\n'){
          if (currentLine.length()==0){
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println("Connection: close");
            client.println();
 
            if (header.indexOf("GET /2/on")>=0){
              Serial.println("on");
              output2="on";
              digitalWrite(output, HIGH);
            }else if (header.indexOf("GET /2/off")>=0){
              Serial.println("off");
              output2="off";
              digitalWrite(output, LOW);
            }

以下是html

client.println("<!DOCTYPE html><html>");
client.println("<style>html {text-align: center;font-family: Arial;display: inline-block;margin: auto;}");
client.println(".button {background-color: #e0e252; border: none;color: white;padding: 15px 35px;");
client.println("text-align: center;text-decoration: none;display: inline-block;font-size: 16px;}");
client.println(".button2 {background-color: #b0b1a2;padding: 15px 32px;}</style></head>");

client.println("<body><h1>ESP32 Web Server</h1>");

client.println("<p>GPIO-2  "+output2+"</p>");
   
if (output2=="off") {
  client.println("<p><a href=\"/2/on\"><button class=\"button\">ON</button></a></p>");
  client.println("<p><a href=\"/2/off\"><button class=\"button button2\">OFF</button></a></p>");
} else if (output2=="on"){
  client.println("<p><a href=\"/2/on\"><button class=\"button button2\">ON</button></a></p>");
  client.println("<p><a href=\"/2/off\"><button class=\"button\">OFF</button></a></p>");
}
client.println("</body></html>");