测试

[xiezuoru]

在这里提问

[408881465]

我尝试在ESP8266上用pubsubclient连接Siot，试了好几次都没有成功，一直返回**Attempting MQTT connection...failed, rc=-2 try again in 5 seconds** ，应该是连接失败。但是我用[pubsubclient](https://github.com/knolleary/pubsubclient)连接[mosquitto](https://mosquitto.org/download/)MQTT broker没有问题。不知什么原因？

pubsubclient连接SIoT测试代码如下：

`#include <ESP8266WiFi.h>
#include "PubSubClient.h"

const char* ssid = "mywifi";//WIFI名字
const char* password = "wifimima";//WIFI密码
const char* mqtt_server = "192.168.1.23";//MQTT服务器IP
const int mqtt_server_port = 1883;//MQTT服务器端口
const char* username = "siot";//MQTT用户名
const char* passward = "dfrobot";//MQTT用户密码
#define ID_MQTT "175867613117375488" //MQTT的Client ID

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;

//灯光函数及引脚定义
void turnOnLed();
void turnOffLed();
const int B_led = 2;

void setup_wifi() {
delay(10);
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);

WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}

Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length) {
Serial.print("Message arrived [");
Serial.print(topic);
Serial.print("] ");
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
}
Serial.println();

// Switch on the LED if an 1 was received as first character
if ((char)payload[0] == '0') {//如果接收数字“1”，亮灯
turnOffLed();//开灯函数

}else if ((char)payload[0] == '1') {
turnOnLed();//关灯函数
}

}

void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Attempt to connect
if (client.connect(ID_MQTT,username,passward)) {
Serial.println("connected");

  client.subscribe("xzr/led");//主题
} else {
  Serial.print("failed, rc=");
  Serial.print(client.state());
  Serial.println(" try again in 5 seconds");
  // Wait 5 seconds before retrying
  delay(5000);
}

}
}

void setup() {
pinMode(B_led,OUTPUT);

Serial.begin(115200);
setup_wifi();
client.setServer(mqtt_server,mqtt_server_port);
client.setCallback(callback);
digitalWrite(B_led,HIGH);
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();

}

//打开灯泡
void turnOnLed(){

digitalWrite(B_led,LOW);
}
//关闭灯泡
void turnOffLed(){
digitalWrite(B_led,HIGH);
}

`

[xiezuoru]

我可以确定的是，SIoT没有问题，ESP8266也是能够正常连SIoT的，因为df的obloq模块就是基于ESP8266。因为我手头没有8266模块，也没办法来帮助你。