Arduino Due + ESP8266 web server controlled LED

It's a web server using Arduino Due + ESP8266 WiFi module, act as web server to turn ON/OFF Arduino Due on-board LED. It can be controlled by a Android App (in my another blog post: Arduino-er - Android App to control Arduino+ESP8266 web connected LED).


The ESP8266 set in CWMODE=2, its IP should be 192.168.4.1 by default.

Note: It have problem if client side sent command too fast, in connection close and connect too close.

Connection:

Due8266WebControlLed_AP.ino

/*
Arduino Due - ESP 8266 WiFi Module

Act as AP mode, CWMODE=2

Serial (Tx/Rx) communicate to PC via USB
Serial3 (Tx3/Rx3) connect to ESP8266
Tx3 - ESP8266 Rx
Rx3 - ESP8266 Tx
ESP8266 CH_PD Connect to ESP8266 VCC

for firmware:
"v0.9.5.2 AT Firmware"
(http://goo.gl/oRdG3s)
AT version:0.21.0.0
SDK version:0.9.5

*/

#define ESP8266 Serial3

int LED = 13;

boolean FAIL_8266 = false;

#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);
  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+CWMODE=2");
      delay(1000);
      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");
        
      FAIL_8266 = false;
    }else{
      Serial.println("Module have no response.");
      delay(500);
      FAIL_8266 = true;
    }
  }while(FAIL_8266);
  
  digitalWrite(LED, HIGH);
  ESP8266.setTimeout(1000);
}

void loop(){

  if(ESP8266.available()) // check if the esp is sending a message 
  {
    Serial.println("Something received");
    delay(1000);
    if(ESP8266.find("+IPD,"))
    {
      String action;
      
      Serial.println("+IPD, found");
      int connectionId = ESP8266.read()-48;
      Serial.println("connectionId: " + String(connectionId));
      
      ESP8266.find("led=");
      char s = ESP8266.read();
      if(s=='0'){
        action = "led=0";
        digitalWrite(LED, LOW);
      }else if(s=='1'){
        action = "led=1";
        digitalWrite(LED, HIGH);
      }else{
        action = "led=?";
      }
      
      Serial.println(action);
      sendHTTPResponse(connectionId, action);
      
      //Close TCP/UDP
      //String cmdCIPCLOSE = "AT+CIPCLOSE="; 
      //cmdCIPCLOSE += connectionId;
      //sendESP8266Cmdln(cmdCIPCLOSE, 1000);
    }
  }
  
}

void sendHTTPResponse(int id, String content)
{
  String response;
  response = "HTTP/1.1 200 OK\r\n";
  response += "Content-Type: text/html; charset=UTF-8\r\n"; 
  response += "Content-Length: ";
  response += content.length();
  response += "\r\n";
  response +="Connection: close\r\n\r\n";
  response += content;

  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;
}

//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);
  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("==============================");
}

Related:
- Standalone ESP8266/ESP-12 (without controller/Arduino): web control on-board LED