ESP8266 펌웨어로 웹서버 기능을 구현한 예
아두이노 IDE를 이용한 ESP8266 펌웨어 개발환경을 구성하는 방법은 이 링크를 눌러 확인하세요
ESP8266 모듈의 펌웨어가 웹서버로 기능하여 웹브라우저의 요청을 처리하여 응답 문자열과 이미지(*.svg)를 웹브라우저 화면에 출력하는 예
/*
* Copyright (c) 2015, Majenko Technologies
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice, this
* list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* * Neither the name of Majenko Technologies nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>
const char *ssid = "201-1203-office-net";
const char *password = "my_office_pwd";
ESP8266WebServer server ( 80 );
const int led = 13;
void handleRoot()
{
digitalWrite ( led, 1 );
char temp[400];
int sec = millis() / 1000;
int min = sec / 60;
int hr = min / 60;
snprintf ( temp, 400,
"<html>\
<head>\
<meta http-equiv='refresh' content='5'/>\
<title>ESP8266 Demo</title>\
<style>\
body { background-color: #cccccc; font-family: Arial, Helvetica, Sans-Serif; Color: #000088; }\
</style>\
</head>\
<body>\
<h1>Hello from ESP8266!</h1>\
<p>Uptime: %02d:%02d:%02d</p>\
<img src=\"/test.svg\" />\
</body>\
</html>",
hr, min % 60, sec % 60
);
server.send ( 200, "text/html", temp );
digitalWrite ( led, 0 );
}
void handleNotFound()
{
digitalWrite ( led, 1 );
String message = "File Not Found\n\n";
message += "URI: ";
message += server.uri();
message += "\nMethod: ";
message += ( server.method() == HTTP_GET ) ? "GET" : "POST";
message += "\nArguments: ";
message += server.args();
message += "\n";
for ( uint8_t i = 0; i < server.args(); i++ )
{
message += " " + server.argName ( i ) + ": " + server.arg ( i ) + "\n";
}
server.send ( 404, "text/plain", message );
digitalWrite ( led, 0 );
}
void setup ( void )
{
pinMode ( led, OUTPUT );
digitalWrite ( led, 0 );
Serial.begin ( 115200 );
WiFi.begin ( ssid, password );
Serial.println ( "" );
// Wait for connection
while ( WiFi.status() != WL_CONNECTED )
{
delay ( 500 );
Serial.print ( "." );
}
Serial.println ( "" );
Serial.print ( "Connected to " );
Serial.println ( ssid );
Serial.print ( "IP address: " );
Serial.println ( WiFi.localIP() );
if ( MDNS.begin ( "esp8266" ) )
{
Serial.println ( "MDNS responder started" );
}
server.on ( "/", handleRoot );
server.on ( "/test.svg", drawGraph );
server.on ( "/inline", []() {
server.send ( 200, "text/plain", "this works as well" );
} );
server.onNotFound ( handleNotFound );
server.begin();
Serial.println ( "HTTP server started" );
}
void loop ( void )
{
server.handleClient();
}
void drawGraph()
{
String out = "";
char temp[100];
out += "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" width=\"400\" height=\"150\">\n";
out += "<rect width=\"400\" height=\"150\" fill=\"rgb(250, 230, 210)\" stroke-width=\"1\" stroke=\"rgb(0, 0, 0)\" />\n";
out += "<g stroke=\"black\">\n";
int y = rand() % 130;
for (int x = 10; x < 390; x+= 10)
{
int y2 = rand() % 130;
sprintf(temp, "<line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke-width=\"1\" />\n", x, 140 - y, x + 10, 140 - y2);
out += temp;
y = y2;
}
out += "</g>\n</svg>\n";
server.send ( 200, "image/svg+xml", out);
}위의 코드에 시리얼 통신 속도가 115200으로 설정되어 있으므로 아두이노 IDE의 시리얼 모니터 화면 하단에서 통신 속도를 115200으로 설정해야만 ESP8266 모듈이 시리얼 통신으로 출력한 메시지를 확인할 수 있다
..........
Connected to 201-1203-home-net
IP address: 192.168.0.12
MDNS responder started
HTTP server started
웹브라우저로 접속한 결과 화면
http://192.168.0.12 으로 접속한 결과
http://192.168.0.12/test.svg 으로 접속한 결과
http://192.168.0.12/inline 으로 접속한 결과
