string - 努力让 Arduino Uno 上的 ESP8266 与 AT 通信可靠地工作

问题描述

我正在努力将 ESP8266 连接到作为网络服务器可靠工作的 Arduino Uno。我的 ESP8266 的固件是 1.1.1 - 我目前没有更新它的选项（或知识）。下面是我的代码。如果我提供一个小字符串，它几乎不会起作用。但是，如果我尝试从浏览器加载页面三到四次，它通常会关闭连接或永远加载（崩溃？）。最终，我需要提供一个嵌入了 json 的网页，该网页将加载由 esp8266 提供的第二个页面，一个 json 文件。我有一个工作演示，但在几次检索后它崩溃了。我知道我的 html 页面对于字符串来说太长了，所以一直试图转移到 PROGMEM，最初只用一个短字符串进行测试。我正在正确存储和检索它（我认为，至少我可以Serial.print它）但是一旦我尝试将其写入 ESP8266，我的浏览器中就会出现永无止境的负载。

我在哪里错了？是导致问题的字符串/PROGMEM 还是我在 AT 命令中缺少的其他内容（例如某种 ping 以保持连接打开）？

//load softserial library
#include <SoftwareSerial.h>

#include <avr/pgmspace.h>


//set a boolean constant variable to true
//#define DEBUG true
const boolean DEBUG = true;

//RX (pin 2) goes to TX on esp8266, TX (pin 3) goes to RX on esp8266
SoftwareSerial esp8266(2, 3);

//input from the photoresistor
//int photoresistorpin = 0;

//create a PROGMEM variable
//String WEBPAGE = "hello";
static const char PROGMEM WEBPAGE[] = {"hello"};

/*
static const char WEBPAGE[] PROGMEM = R"rawliteral(
<html>
<head>
<meta name="viewport" content="width=device-width, minimumscale=1, maximum-scale=1, initial-scale=1">
</head>
  <h1>Light:</h1><div id="light"></div>
<script>
function loadDoc()
{
  var xhttp = new XMLHttpRequest();
  xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) 
    {
      var obj = JSON.parse(this.responseText);
      document.getElementById('light').innerHTML = obj.data[0].datavalue;
    }
  };
xhttp.open('GET', 'data.json', true); xhttp.send();
}
var timedEvent = setInterval(function() { loadDoc(); }, 5000);
</script>
</body>
</html>
)rawliteral";
*/
//const int WEBPAGE_len = sizeof(WEBPAGE)/sizeof(WEBPAGE[0]);



void setup()
{
  //open the serial port
  Serial.begin(115200);

  //print setup started in the serial monitor
  Serial.println("Setup started");

  //start esp8266 module (note: your esp's baud rate might be different)
  esp8266.begin(115200);

  //reset esp8266 module
  senddata("AT+RST\r\n", 2000, DEBUG); 

  //set esp8266 as access point mode
  //1 = Station mode (client)
  //2 = Access point mode (host)
  //3 = Access point mode + Station mode
  senddata("AT+CWMODE=2\r\n", 1000, DEBUG); 

  //get ip address for esp8266
  senddata("AT+CIFSR\r\n", 2000, DEBUG);

  //configure esp8266 for multiple connections
  senddata("AT+CIPMUX=1\r\n", 1000, DEBUG);

  //turn on esp8266 server on port 80
  senddata("AT+CIPSERVER=1,80\r\n", 1000, DEBUG);

  //setup completed
  Serial.println("Setup done");
}


void loop()
{
  //take a reading from the photoresistor
  //int lightval = analogRead(photoresistorpin);
  int lightval = random(1000);

  //to test
  //Serial.println(lightval);

  //is the esp8266 sending a message 
  if (esp8266.available())
  {
    //if received data from esp8266
    if (esp8266.find("+IPD,"))
    {
      //subtract 48 because the read() function returns the ASCII decimal 
      //value and 0 (the first decimal number) starts at 48
      int connectionid = esp8266.read() - 48;

//Serial.println("");
//Serial.println("*****");
//Serial.print("string = ");

      //read the url sent by the client, look for the variable (/)
      String msg;
      esp8266.find("/");
      delay(100);
      msg = esp8266.readStringUntil(' ');
      String pathrequested = msg.substring(0);

Serial.println("*****");
Serial.println(pathrequested);
Serial.println("*****");


        //create a senddata string to send the webpage to the esp8266
        String cipsend = "AT+CIPSEND=" + String(connectionid) + ",";

        //cipsend += WEBPAGE.length();
        cipsend += strlen_P(WEBPAGE);
        cipsend += "\r\n";
        Serial.println(cipsend);

        char buffer[1000];
        strcpy_P(buffer, WEBPAGE);
        Serial.println(buffer);

        //senddata(cipsend, 500, DEBUG);
        //senddata(WEBPAGE, 500, DEBUG);
        senddata(buffer, 500, DEBUG);

        //create a string closecommand with the connection id and send it
        String closecommand = "AT+CIPCLOSE=" + String(connectionid) + "\r\n";
        senddata(closecommand, 500, DEBUG);

        //increment the count
        //count++;

    }
  }


}


void senddata(String command, const int timeout, boolean debug)
{
  //send the received command to the esp8266
  esp8266.print(command);

  //set int variable to the number of millisends since Arduino began
  long int time = millis();

  //while the time and the timeout is less than the number of millisends since Arduino began
  while((time + timeout) > millis())
  {
    //while the esp8266 is sending messages
    while(esp8266.available())
    {
      //display output in the serial window 
      Serial.write(esp8266.read());
    }  
  }
}

标签： stringarduinoesp8266progmem

string - 努力让 Arduino Uno 上的 ESP8266 与 AT 通信可靠地工作

问题描述

解决方案

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