c - Arduino 和 ESP8266 HTTP GET 响应处理

Question

我已成功连接服务器，但无法处理响应数据。 esp8266.find("+PID,") 不起作用。我的循环代码如下:

void loop() {
  String cmd = "AT+CIPSTART=\"TCP\",\""; //make this command: AT+CPISTART="TCP","192.168.88.35",80
  cmd += DST_IP;
  cmd += "\",80\r\n";
  esp8266.print(cmd);
  //wait a little while for 'Linked'
  delay(3000);

  //This is our HTTP GET Request change to the page and server you want to load.
  cmd = "GET /~atolye/wifiModule.php?id=123 HTTP/1.0\r\n";
  cmd += "Host: 159.122.115.70\r\n\r\n";
  esp8266.print("AT+CIPSEND=63\r\n");
  if(esp8266.find(">")) {
    //Send our http GET request
    Serial.println("SENDING THE REQUEST");
    esp8266.print(cmd);
    if(esp8266.find("+IPD,")) {
      Serial.println("\r\nIPD FOUND");
      if(esp8266.find("\"1")) {
        int value = esp8266.read()-48;
        Serial.println("\r\nVALUE FOUND");
        Serial.println(value);
        esp8266.println(value);
      }
    } else {
      Serial.println("\r\n!! IPD NOT FOUND");
    }
  }
  else {
    Serial.println("\r\nERROR > DOESN'T EXIST");
  //Something didn't work...
    esp8266.print("AT+CIPCLOSE\r\n");
  }

}

这是输出:正如您所注意到的，IPD NOT FOUND 在 RESPONSE 到达之前执行。我应该怎么做才能捕获这些数据？提前致谢。

AT+CIPSTART="TCP","159.122.115.70",80

CONNECT

OK
SENDING THE REQUEST

!! IPD NOT FOUND
START="TCP","159.122.115.70",80

busy s...

Recv 103 bytes

SEND OK

+IPD,205:HTTP/1.1 200 OK
Date: Thu, 16 Jun 2016 08:33:19 GMT
Server: Apache/2.4.16 (Unix) OpenSSL/1.0.1e-fips mod_bwlimited/1.4
X-Powered-By: PHP/5.5.30
Connection: close
Content-Type: application/json

"12"CLOSED

Answer 1

问题不在于响应时间。假设有一个通过 AT+CIPSTART 打开的 TCP 连接，以及一个长度为 42 个字符的请求，如下所示:

GET / HTTP/1.0\r\nHost: 77.223.129.195\r\n

在执行之前应将 CIPSEND 设置为字符计数。问题是，\r\n 每个被计为 1 个字节，不应计为 2 个字符。请求由 4 个字符 42-4 = 38 组成。

AT+CIPSEND=38\r\n

排除 2 个字节解决了问题，并在代码检查是否有“+PID”之前成功显示。