MQTT-SN Tools

Command line tools written in C for the MQTT-SN (MQTT for Sensor Networks) protocol.

Supported Features

• QoS 0, 1 and -1
• Keep alive pings
• Publishing retained messages
• Publishing empty messages
• Subscribing to named topic
• Clean / unclean sessions
• Manual and automatic client ID generation
• Displaying topic name with wildcard subscriptions
• Pre-defined topic IDs and short topic names
• Forwarder encapsulation according to MQTT-SN Protocol Specification v1.2.

Limitations

• Packets must be 255 or less bytes long
• No Last Will and Testament
• No QoS 2
• No automatic re-sending of lost packets
• No Automatic gateway discovery

Building

Just run 'make' on a POSIX system.

Publishing

Usage: mqtt-sn-pub [opts] -t <topic> -m <message>

  -d             Increase debug level by one. -d can occur multiple times.
  -f <file>      A file to send as the message payload.
  -h <host>      MQTT-SN host to connect to. Defaults to '127.0.0.1'.
  -i <clientid>  ID to use for this client. Defaults to 'mqtt-sn-tools-' with process id.
  -k <keepalive> keep alive in seconds for this client. Defaults to 10.
  -e <sleep>     sleep duration in seconds when disconnecting. Defaults to 0.
  -m <message>   Message payload to send.
  -l             Read from STDIN, one message per line.
  -n             Send a null (zero length) message.
  -p <port>      Network port to connect to. Defaults to 1883.
  -q <qos>       Quality of Service value (0, 1 or -1). Defaults to 0.
  -r             Message should be retained.
  -s             Read one whole message from STDIN.
  -t <topic>     MQTT-SN topic name to publish to.
  -T <topicid>   Pre-defined MQTT-SN topic ID to publish to.
  --fe           Enables Forwarder Encapsulation. Mqtt-sn packets are encapsulated according to MQTT-SN Protocol Specification v1.2, chapter 5.5 Forwarder Encapsulation.
  --wlnid        If Forwarder Encapsulation is enabled, wireless node ID for this client. Defaults to process id.
  --cport <port> Source port for outgoing packets. Uses port in ephemeral range if not specified or set to 0.

Subscribing

Usage: mqtt-sn-sub [opts] -t <topic>

  -1             exit after receiving a single message.
  -c             disable 'clean session' (store subscription and pending messages when client disconnects).
  -d             Increase debug level by one. -d can occur multiple times.
  -h <host>      MQTT-SN host to connect to. Defaults to '127.0.0.1'.
  -i <clientid>  ID to use for this client. Defaults to 'mqtt-sn-tools-' with process id.
  -k <keepalive> keep alive in seconds for this client. Defaults to 10.
  -e <sleep>     sleep duration in seconds when disconnecting. Defaults to 0.
  -p <port>      Network port to connect to. Defaults to 1883.
  -q <qos>       QoS level to subscribe with (0 or 1). Defaults to 0.
  -t <topic>     MQTT-SN topic name to subscribe to. It may repeat multiple times.
  -T <topicid>   Pre-defined MQTT-SN topic ID to subscribe to. It may repeat multiple times.
  --fe           Enables Forwarder Encapsulation. Mqtt-sn packets are encapsulated according to MQTT-SN Protocol Specification v1.2, chapter 5.5 Forwarder Encapsulation.
  --wlnid        If Forwarder Encapsulation is enabled, wireless node ID for this client. Defaults to process id.
  -v             Print messages verbosely, showing the topic name.
  -V             Print messages verbosely, showing current time and the topic name.
  --cport <port> Source port for outgoing packets. Uses port in ephemeral range if not specified or set to 0.

Dumping

Displays MQTT-SN packets sent to specified port. Most useful for listening out for QoS -1 messages being published by a client.

Usage: mqtt-sn-dump [opts] -p <port>

  -a             Dump all packet types.
  -d             Increase debug level by one. -d can occur multiple times.
  -p <port>      Network port to listen on. Defaults to 1883.
  -v             Print messages verbosely, showing the topic name.

Serial Port Bridge

The Serial Port bridge can be used to relay packets from a remote device on the end of a serial port and convert them into UDP packets, which are sent and received from a broker or MQTT-SN gateway.

Usage: mqtt-sn-serial-bridge [opts] <device>

  -b <baud>      Set the baud rate. Defaults to 9600.
  -d             Increase debug level by one. -d can occur multiple times.
  -dd            Enable extended debugging - display packets in hex.
  -h <host>      MQTT-SN host to connect to. Defaults to '127.0.0.1'.
  -p <port>      Network port to connect to. Defaults to 1883.
  --fe           Enables Forwarder Encapsulation. Mqtt-sn packets are encapsulated according to MQTT-SN Protocol Specification v1.2, chapter 5.5 Forwarder Encapsulation.
  --cport <port> Source port for outgoing packets. Uses port in ephemeral range if not specified or set to 0.

License

MQTT-SN Tools is licensed under the MIT License.