上传数据到yeelink时总是提示failed connect

用的是seeeduino的板和seeeduino的wifi shield RN171
按照产品提供的例程上传传感器数据到yeelink，可是总是提示failed connect，请各位大咖帮我看看哪里不对好吗(｡´・ω・`)
这是代码
#include <math.h>
#include <Arduino.h>
#include <SoftwareSerial.h>
#include <WiFly.h>
#include "HTTPClient.h"

#define SSID      "这不是你的WiFi"
#define KEY       "1234567890"
#define AUTH      WIFLY_AUTH_WPA2_PSK // WIFLY_AUTH_WPA1, WIFLY_AUTH_WEP, WIFLY_AUTH_OPEN
#define HTTP_POST_HEADERS    "U-ApiKey:686fc75226ee61988f95ccf609bef8b6\r\n"     
#define HTTP_POST_URL "http://api.yeelink.net/v1.0/device/14993/sensor/25699/datapoints"

const int temsensor=A0;
int a;
float temperature;
int B=3975;                 
float resistance;

SoftwareSerial uart(2, 3);
WiFly wifly(uart);
HTTPClient http;//建一个HTTPClient的对象http
char get;

void setup()
{
  Wire.begin(9600);
  uart.begin(9600);
  Serial.begin(9600);  

  Serial.println("------- WIFLY HTTP --------");
  Serial.println("Try to join " SSID"...");
  if (!wifly.isAssociated(SSID)) {
    while (!wifly.join(SSID, KEY, AUTH)) {
      Serial.println("Failed to join " SSID);
      Serial.println("Wait 1 second and try again...");
    }
    wifly.save();    // save configuration   
  }  // check if WiFly is associated with AP(SSID)
  Serial.println("Connected to " SSID"!\n");
}
unsigned long start_millis = 0;
char post_data_buf[32];
void loop()
{
  if ((millis() - start_millis) < 20000) {
    return;
  } else {
    start_millis = millis();
  }
  a=analogRead(temsensor);
  resistance=(float)(1023-a)*10000/a;
  temperature=1/(log(resistance/10000)/B+1/298.15)-273.15;
  Serial.print("Current temperature is ");
  Serial.println(temperature);

  Serial.println("\r\n\r\nTry to post data to url - " HTTP_POST_URL);
  Serial.println("-------------------------------");

  int whole=int(temperature);int fract=int(temperature*100)%100;
  snprintf(post_data_buf, sizeof(post_data_buf), "{\"value\": %d.%d}\r\n",whole,fract+1);
  Serial.println(post_data_buf);  
  while (http.post(HTTP_POST_URL, HTTP_POST_HEADERS, post_data_buf,10000) < 0){}

  char r;
  while (wifly.receive((uint8_t *)&r, 1, 1000) == 1) {
    Serial.print(r);
  }
  delay(10000);
}

就是执行到倒数第七行的时候提示failed connect
然后我看了下 HTTPClient.cpp
找到了failed connect的原因
if (!wifly->connect(host, port, timeout)) {
    DBG("Failed to connect.\r\n");
可是看不懂事什么意思_(:з」∠)_