1. Overview of AT commands for MQTT

Command                                  Description

AT+MQTTCONN           Send MQTT connection packet

AT+MQTTSUB               Send MQTT subscribe packet

AT+MQTTPUB               Send MQTT publish packet

AT+MQTTDISCONN      Disconnect MQTT

2. Detailed Descriptions of AT Commands

2.1 AT+MQTTCONN       Send MQTT connection packet

AT+MQTTCONN=<host>,<port>,<clientid>,<aliveSeconds>,<cleansession>,<username>,<password>

Response :

success            OK

failure               +CME ERROR:<err>

Parameters:     

<host>                   MQTT server name or server IP address                

<port>                   MQTT server port

<clientid>              Client ID, should be unique

<aliveSeconds>    Keep alive interval

<cleansession>     Cean session, can be 0 or 1

<username>          User name (option)

<password>          Password (option)

Example:

1.Not enter username and password

AT+MQTTCONN="www.mqtt-dashboard.com",1883,"12345",120,0

OK

2. Enter username and password

AT+MQTTCONN="www.mqtt-dashboard.com",1883,"12345",120,0,"Ai-thinker","123456"

OK

2.2 AT+MQTTSUB               Send MQTT subscribe packet

AT+MQTTSIN=<topic>,<sub>,<qos>

Response :

success            OK

failure               +CME ERROR:<err>

Parameters:     

<topic>                   Topic of subscribe message                

<sub>                      Subscribe flag, can be 0 or 1

<qos>                      Message QoS, can be 0, 1 or 2.

Example:

AT+MQTTSUB="test",1,0

+MQTTPUBLISH:1,app, 10,1234567890
OK

2.3 AT+MQTTPUB               Send MQTT publish packet

AT+MQTTPUB=<topic>,<payload>,<qos>,<dup>,<remain>

Response :

success            OK

failure               +CME ERROR:<err>

Parameters:     

<topic>                   Topic of subscribe message 

<payload>              Publish message

<dub>                     Duplicate flag, can be 0 or 1

<qos>                     Message QoS, can be 0, 1 or 2.

<remain>                Retained flag, can be 0 or 1.

Example:

AT+MQTTPUB="test","123456",0,0,0

OK

AT+MQTTPUB=<topic>,<payloadlength>,<payload>,<qos>,<dup>,<remain>

Response :

success            OK

failure               +CME ERROR:<err>

Parameters:     

<topic>                   Topic of subscribe message 

<payloadlength>    Publish message length

<payload>              Publish message

<dub>                     Duplicate flag, can be 0 or 1

<qos>                     Message QoS, can be 0, 1 or 2.

<remain>                Retained flag, can be 0 or 1.

Example:

AT+MQTTPUB="test",5,0,0,0

>12345

OK

2.4 AT+MQTTDISCONN      Disconnect MQTT

Response :

success            OK

failure               +CME ERROR:<err>

2.5 Example of the A9 A9G MQTT

AT+ CGATT=1     //connect to the network

OK

AT+CGDCONT=1,"IP","CMNET"  // Set PDP Parameters

OK

AT+CGACT=1,1    //Active the PDP

OK

AT+MQTTCONN="www.anthinkerwx.com",1883,"12345",120,0,”ai-thinker”,”123456”      //Client connect to the mqtt server

OK

AT+MQTTPUB="test","124563",0,0,0   //Publish a massage

OK

AT+MQTTSUB="test",1,0   //Send MQTT subscribe packet

OK

AT+MQTTDISCONNN    // Disconnect the mqtt server

OK

Wire the DHT11 to the ESP-12S A9G GPRS GPS Node as shown in the following schematic diagram.

Also install the Noao SIM card and Plug the Lipo battery and USB.

ThingSpeak is where we are going to store the data collected by our thing and where we can see the data that we collected. Visit ThingSpeak.com and Sign Up for an account. This will just take a minute and user accounts are free. Once you have a user account, you need to create a channel. ThingSpeak channels are where data gets stored. Create a new channel by selecting Channels, My Channels, and then New Channel. Name the channel, “ESP-12S A9G DHT11” and name Field 1, “temp”, Field 2:"hum".Click “Save Channel” at the bottom to finish the process.

we need to install some software to be able to program the ESP8266. Visit Arduino.cc and install the Arduino IDE.

More detail please refer our wiki.

Downlaod and Installing the Adafruit DHT11 and  Sensor Library. Unzip the .zip file and place them to the Arduino librarys.

Copy the following code to your Arduino IDE but don’t upload it yet. First, you need to make some modifications to make it work.