EMQPUBLISH – publish data to a message topic

Publish data to a created message topic. Data is sent to your thing in AWS IoT Console.

Type Syntax Returned Result
Test

AT+EMQPUBLISH=?

OK

 

+EMQPUBLISH: (0-7),(0-1),<pubdata>
Read

AT+EMQPUBLISH?

OK

Write

AT+EMQPUBLISH=(0-7),(0-1),<pubdata>

where:

  • (0-7) is the publish index number
  • (0-1) is the Quality of Service, either:
    • 0 – sends the message without guaranteeing message receipt. The message is not stored on the sender, and is not acknowledged.
    • 1 – guarantees the message is delivered at least once.

  • <pubdata> – is the published message. The maximum payload length is 1000 characters. All characters must be printable.

    ETM handles <pubdata> as ASCII-hex if it contains an even number of valid ASCII-hex characters (0-9, a-f, A-F). ASCII-hex is converted to binary for transmission.

    ETM handles all other data as text. For text messages, \ (escape characters) are removed.

OK – successfully wrote the command

ERROR – the command failed. Check your syntax, and that you have already set up the publish topic using at+emqpubopen?.

SEND OK – send confirmation relating to Quality of Service. This response is for:

  • QoS=0 – message is published
  • QoS=1 – MQTT broker generates a PUBACK to confirm receipt of the MQTT message

SEND FAIL - send failure for QoS=1 only.

Example

AT+EMQPUBLISH=1,1,"{\"BatteryPower\": \"Low\"}"

OK

 

SEND OK

Where to next?

Related resources