Saturday, June 18, 2016

ESP-05(ESP8266) + Arduino Mega, act as simple web server

Last post introduced ESP-05 (a mini ESP8266 board) with simple testing. This post show a very simple web server on Arduino Mega 2560 + ESP-05.

Basically, it's same as the example of "Arduino + ESP8266 - Web Server (III) with firmware 00200.9.5(b1)", except the baud rate.


Mega_ESP05_Web.ino
/*
Arduino Mega 2560 + ESP-05(ESP8266)

ESP-05 running firmware:
AT version:0.40.0.0(Aug  8 2015 14:45:58)
SDK version:1.3.0
Ai-Thinker Technology Co.,Ltd.
Build:1.3.0.2 Sep 11 2015 11:48:04

Connection between Mega & ESP-05, 
refer "Connect with Arduino Mega 2560 via Level Converter" in:
http://goo.gl/wtG89i

Mega + ESP_05 act as station, join WiFi AP of my phone.
Once server setup, you can visit the webpage in ESP-05
by visit the IP show in Serial Monitor, under the command:
AT+CIFSR
+CIFSR:STAIP,"192.168.43.15"

If always show "Module have no response.",
check your connection, or reset ESP-05 by power OFF and ON.

 */
#define ASCII_0 48
#define ESP8266 Serial3

//WiFi hotspot setting on my phone
String SSID = "ssid";
String PASSWORD = "password";

int LED = 13;

boolean FAIL_8266 = false;

String strHTML1 = "<!doctype html>\
<html>\
<head>\
<title>arduino-er</title>\
</head>\
<body>\
<H1>arduino-er.blogspot.com</H1>";

String strHTML2 = "</body>\
</html>";

//String strHTML = "arduino-er.blogspot.com";

#define BUFFER_SIZE 128
char buffer[BUFFER_SIZE];

void setup() {
  pinMode(LED, OUTPUT);
  
  digitalWrite(LED, LOW);
  delay(300);
  digitalWrite(LED, HIGH);
  delay(200);
  digitalWrite(LED, LOW);
  delay(300);
  digitalWrite(LED, HIGH);
  delay(200);
  digitalWrite(LED, LOW);

  do{
    Serial.begin(115200);
    ESP8266.begin(115200);
  
    //Wait Serial Monitor to start
    while(!Serial);
    Serial.println("--- Start ---");

    ESP8266.println("AT+RST");
    delay(1000);
    if(ESP8266.find("ready"))
    {
      Serial.println("Module is ready");
      
      ESP8266.println("AT+GMR");
      delay(1000);
      clearESP8266SerialBuffer();
      
      ESP8266.println("AT+CWMODE=1");
      delay(2000);
      
      //Quit existing AP, for demo
      Serial.println("Quit AP");
      ESP8266.println("AT+CWQAP");
      delay(1000);
      
      clearESP8266SerialBuffer();
      if(cwJoinAP())
      {
        Serial.println("CWJAP Success");
        FAIL_8266 = false;
        
        delay(3000);
        clearESP8266SerialBuffer();
        //Get and display my IP
        sendESP8266Cmdln("AT+CIFSR", 1000);  
        //Set multi connections
        sendESP8266Cmdln("AT+CIPMUX=1", 1000);
        //Setup web server on port 80
        sendESP8266Cmdln("AT+CIPSERVER=1,80",1000);
        
        Serial.println("Server setup finish");
      }else{
        Serial.println("CWJAP Fail");
        delay(500);
        FAIL_8266 = true;
      }
    }else{
      Serial.println("Module have no response.");
      delay(500);
      FAIL_8266 = true;
    }
  }while(FAIL_8266);
  
  digitalWrite(LED, HIGH);
  
  //set timeout duration ESP8266.readBytesUntil
  ESP8266.setTimeout(1000);
}

void loop(){
  int connectionId;
  
  if(ESP8266.readBytesUntil('\n', buffer, BUFFER_SIZE)>0)
  {
    Serial.println("Something received");
    Serial.println(buffer);
    if(strncmp(buffer, "+IPD,", 5)==0){
      Serial.println("+IPD, found");
      sscanf(buffer+5, "%d", &connectionId);
      Serial.println("connectionId: " + String(connectionId));
      delay(1000);
      clearESP8266SerialBuffer();
      
      sendHTTPResponse(connectionId, strHTML1);
      sendHTTPResponse(connectionId, "<hr/>-END-<br/>");
      sendHTTPResponse(connectionId, strHTML2);

      //Close TCP/UDP
      String cmdCIPCLOSE = "AT+CIPCLOSE="; 
      cmdCIPCLOSE += connectionId;
      sendESP8266Cmdln(cmdCIPCLOSE, 1000);
    }
  }
}

void sendHTTPResponse(int id, String response)
{
  String cmd = "AT+CIPSEND=";
  cmd += id;
  cmd += ",";
  cmd += response.length();
  
  Serial.println("--- AT+CIPSEND ---");
  sendESP8266Cmdln(cmd, 1000);
  
  Serial.println("--- data ---");
  sendESP8266Data(response, 1000);
}

boolean waitOKfromESP8266(int timeout)
{
  do{
    Serial.println("wait OK...");
    delay(1000);
    if(ESP8266.find("OK"))
    {
      return true;
    }

  }while((timeout--)>0);
  return false;
}

boolean cwJoinAP()
{
  String cmd="AT+CWJAP=\"" + SSID + "\",\"" + PASSWORD + "\"";
  ESP8266.println(cmd);
  return waitOKfromESP8266(10);
}

//Send command to ESP8266, assume OK, no error check
//wait some time and display respond
void sendESP8266Cmdln(String cmd, int waitTime)
{
  ESP8266.println(cmd);
  delay(waitTime);
  clearESP8266SerialBuffer();
}

//Basically same as sendESP8266Cmdln()
//But call ESP8266.print() instead of call ESP8266.println()
void sendESP8266Data(String data, int waitTime)
{
  //ESP8266.print(data);
  ESP8266.print(data);
  delay(waitTime);
  clearESP8266SerialBuffer();
}

//Clear and display Serial Buffer for ESP8266
void clearESP8266SerialBuffer()
{
  Serial.println("= clearESP8266SerialBuffer() =");
  while (ESP8266.available() > 0) {
    char a = ESP8266.read();
    Serial.write(a);
  }
  Serial.println("==============================");
}





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