MQTT AT command set¶
This chapter introduces the driver MQTT command set. This command set will be adapted differently for different modules. For specific differences, please move to：Firmware iterations and differences。
AT+MQTT：MQTT configuration and connection
AT+MQTTPUB：publish MQTT message
AT+MQTTPUBRAW：publish MQTT messages of specified length
AT+MQTTSUB：subscribe to MQTT messages
AT+MQTTUNSUB：unsubscribe from MQTT messages
AT+MQTT configuration and connection¶
Configuration command¶
Command：
//Configuration parameters
AT+MQTT=<key>,<data>
Response：
OK
Parameters¶
- <key>：MQTT parameter.
1：Set the domain name or IP of the connection
2：Set the server port number
- 3：Set the connection method
reserved, temporarily default 1: use tcp connection
4：Set Client ID
- 5：Set User Name
Maximum length 63 bytes
- 6：Set Login Password
Maximum length 63 bytes
- 7：set the testament message in the format AT+MQTT=7,<LWT_topic>,<LWT_qos>,<LWT_Retained>,<LWTpayload>
LWT_topic：testament subject(No testament required here set to””)
LWT_qos：testament QOS(0/1/2)
LWT_Retained：testament retained(0/1)
LWTpayload：testament message content
<data>：set parameters.
Description¶
Configure MQTT connection parameters.
Execute command¶
Command：
//Enable connection
AT+MQTT
Response：
OK
Example¶
//Set domain name
AT+MQTT=1,192.168.202.10
OK
//Set port number
AT+MQTT=2,1883
OK
//Set the connection method
AT+MQTT=3,1
OK
// Set user ID
AT+MQTT=4,client_id
OK
// Set MQTT User Name
AT+MQTT=5,admin
OK
//Set MQTT password
AT+MQTT=6,public
OK
//Set Testament Theme LWTTOPIC，qos0，open retained，the load message is 123456；Note: The message to cancel the testament is set to AT+MQTT=7,"",0,0,""
AT+MQTT=7,"LWTTOPIC",0,1,"123456"
OK
//Query MQTT connection and configuration
AT+MQTT?
+MQTT:0,192.168.202.10,1883,1,client_id,admin,public
OK
//Connect MQTT
AT+MQTT
OK
//MQTT connection successful
+EVENT:MQTT_CONNECT
Query command¶
Command：
AT+MQTT?
Response：
+MQTT:<MQTT_status>,<Host_name>,<Port>,<scheme>,<client_id>,<username>,<password>,<LWT_topic>,<LWT_qos>,<LWT_Retained>,<LWTpayload>
OK
Parameters¶
- <MQTT_status>：MQTT connection status.
0：Initial State
1：Connecting
2：Subscribing to Messages
3：Connection Successfully
<Host_name>：server domain name.
<Port>：the port number of the server.
- <scheme>：connection method
1：TCP connection
<client_id>：MQTT user ID.
<username>：MQTT username.
<password>：MQTT password.
<LWT_topic>：subject of testament.
<LWT_qos>：testament QOS。
<LWT_Retained>：testament retained。
<LWTpayload>：testament message content
Description¶
Note: MQTT parameters need to be set before performing the connection. If the current MQTT task has been started and executed again, it will be reconnected (if the server is changed, it is recommended to delete all subscriptions before reconnecting)
Note: This is an asynchronous connection. The display OK only means that the MQTT task is started. The connection status needs to be through AT + MQTT? Query or wait for URC data“+EVENT:MQTT_CONNECT
Example¶
AT+MQTT? //Query MQTT Connection and Configuration
+MQTT:0,192.168.202.10,1883,1,client_id,admin,public,LWTTOPIC,0,1,123456
OK
AT+MQTTPUB releases MQTT messages¶
Execute command¶
Command：
AT+MQTTPUB=<topic>,<qos>,<Retained>,<payload>
Response：
OK
Parameters¶
<topic>：the topic to be published.
<qos>：qos grade(0,1,2)。
- <Retained>：
0：General message
1：Retained message
<payload>：data content
Description¶
Publish MQTT messages.
Example¶
AT+MQTTPUB=testtopic,1,0,456
OK
AT+MQTTPUBRAW publishes MQTT messages of specified length¶
Execute command¶
Command：
AT+MQTTPUBRAW=<topic>,<qos>,<Retained>,<length>
Response：
OK
Parameters¶
<topic>：the topic to be published.
<qos>：qos grade(0,1,2)。
- <Retained>：
0：General message
1：Retained message
<length>：Data length
Description¶
Publish MQTT messages of specified length.
Example¶
AT+MQTTPUBRAW=testtopic,1,0,10 //Send 10 bytes of data to testtopic
> //After receiving this character, start entering the data to be sent
OK //After receiving 10 bytes of data, data (which can be any data) will be sent, and OK will be displayed after sending.
AT+MQTTSUB Subscribe to MQTT Messages¶
Execute command¶
Command：
AT+MQTTSUB=<topic>,<qos>
Response：
OK
Parameters¶
<topic>：topic to subscribe.
<qos>：qos grade(0,1,2)。
Description¶
Configure MQTT subscription topics.
Example¶
AT+MQTTSUB=testtopic0,0
OK
Query command¶
Command：
AT+MQTTSUB?
Response：
<status>,<Topic>
...
OK
Parameters¶
- <status>：Subscription status.
0：Initialization Status
1：Subscription (first subscription)
2：Subscribe (re-subscribe after disconnection and reconnection)
3：Subscription Successful
<Topic>：Subscribed topics.
Description¶
Query MQTT subscription topics that have been configured.
Example¶
AT+MQTTSUB?
3,testtopic0
3,testtopic1
OK
AT+MQTTUNSUB unsubscribe from MQTT messages¶
Execute command¶
Command：
AT+MQTTUNSUB=<topic>
Response：
OK
Parameters¶
<topic>：unsubscribed topics.
Description¶
unsubscribe from MQTT messages.
Example¶
AT+MQTTSUB=testtopic0
OK