| .. _mqtt-sn-publisher-sample: |
| |
| MQTT-SN Publisher |
| ################# |
| |
| Overview |
| ******** |
| |
| `MQTT <http://mqtt.org/>`_ (MQ Telemetry Transport) is a lightweight |
| publish/subscribe messaging protocol optimized for small sensors and |
| mobile devices. |
| |
| MQTT-SN can be considered as a version of MQTT which is adapted to |
| the peculiarities of a wireless communication environment. While MQTT |
| requires a reliable TCP/IP transport, MQTT-SN is designed to be usable |
| on any datagram-based transport like UDP, ZigBee or even a plain UART |
| (with an additional framing protocol). |
| |
| The Zephyr MQTT-SN Publisher sample application is a MQTT-SN v1.2 |
| client that sends MQTT-SN PUBLISH messages to a MQTT-SN gateway. |
| It also SUBSCRIBEs to a topic. |
| See the `MQTT-SN v1.2 spec`_ for more information. |
| |
| .. _MQTT-SN v1.2 spec: https://www.oasis-open.org/committees/download.php/66091/MQTT-SN_spec_v1.2.pdf |
| |
| The source code of this sample application can be found at: |
| :zephyr_file:`samples/net/mqtt_sn_publisher`. |
| |
| Requirements |
| ************ |
| |
| - Linux machine |
| - MQTT-SN gateway, like Eclipse Paho |
| - Mosquitto server: any version that supports MQTT v3.1.1. This sample |
| was tested with mosquitto 1.6. |
| - Mosquitto subscriber |
| - LAN for testing purposes (Ethernet) |
| |
| Build and Running |
| ***************** |
| |
| Currently, this sample application only supports static IP addresses. |
| Open the :file:`prj.conf` file and set the IP addresses according |
| to the LAN environment. |
| |
| You will also need to start a MQTT-SN gateway. With paho, you can either |
| build it from source - see `PAHO MQTT-SN Gateway`_ - or run an unofficial |
| docker image, like `kyberpunk/paho`_. |
| |
| .. _PAHO MQTT-SN Gateway: https://www.eclipse.org/paho/index.php?page=components/mqtt-sn-transparent-gateway/index.php |
| .. _kyberpunk/paho: https://hub.docker.com/r/kyberpunk/paho |
| |
| On your Linux host computer, open 3 terminal windows. At first, start mosquitto: |
| |
| .. code-block:: console |
| |
| $ sudo mosquitto -v -p 1883 |
| |
| Then, in another window, start the gateway, e.g. by using docker: |
| |
| .. code-block:: console |
| |
| $ docker run -it -p 10000:10000 -p 10000:10000/udp --name paho -v $PWD/gateway.conf:/etc/paho/gateway.conf:ro kyberpunk/paho |
| |
| Then, locate your zephyr directory and type: |
| |
| .. zephyr-app-commands:: |
| :zephyr-app: samples/net/mqtt_sn_publisher |
| :board: native_posix_64 |
| :goals: build -t run |
| :compact: |
| |
| Optionally, use any MQTT explorer to connect to your broker. |
| |
| Sample output |
| ============= |
| |
| This is the applications output: |
| |
| .. code-block:: console |
| |
| WARNING: Using a test - not safe - entropy source |
| *** Booting Zephyr OS build zephyr-v3.2.0-279-gc7fa387cea81 *** |
| [00:00:00.000,000] <inf> net_config: Initializing network |
| [00:00:00.000,000] <inf> net_config: IPv4 address: 172.18.0.20 |
| [00:00:00.000,000] <inf> mqtt_sn_publisher_sample: MQTT-SN sample |
| [00:00:00.000,000] <inf> mqtt_sn_publisher_sample: Network connected |
| [00:00:00.000,000] <inf> mqtt_sn_publisher_sample: Waiting for connection... |
| [00:00:00.000,000] <inf> mqtt_sn_publisher_sample: Connecting client |
| [00:00:00.510,000] <inf> net_mqtt_sn: Decoding message type: 5 |
| [00:00:00.510,000] <inf> net_mqtt_sn: Got message of type 5 |
| [00:00:00.510,000] <inf> net_mqtt_sn: MQTT_SN client connected |
| [00:00:00.510,000] <inf> mqtt_sn_publisher_sample: MQTT-SN event EVT_CONNECTED |
| [00:00:01.020,000] <inf> net_mqtt_sn: Decoding message type: 19 |
| [00:00:01.020,000] <inf> net_mqtt_sn: Got message of type 19 |
| [00:00:10.200,000] <inf> mqtt_sn_publisher_sample: Publishing timestamp |
| [00:00:10.200,000] <inf> net_mqtt_sn: Registering topic |
| 2f 75 70 74 69 6d 65 |/uptime |
| [00:00:10.200,000] <inf> net_mqtt_sn: Can't publish; topic is not ready |
| [00:00:10.710,000] <inf> net_mqtt_sn: Decoding message type: 11 |
| [00:00:10.710,000] <inf> net_mqtt_sn: Got message of type 11 |
| [00:00:10.710,000] <inf> net_mqtt_sn: Publishing to topic ID 14 |
| [00:00:20.400,000] <inf> mqtt_sn_publisher_sample: Publishing timestamp |
| [00:00:20.400,000] <inf> net_mqtt_sn: Publishing to topic ID 14 |
| |
| This is the output from the MQTT-SN gateway: |
| |
| .. code-block:: console |
| |
| 20221024 140210.191 CONNECT <--- ZEPHYR 0C 04 04 01 00 3C 5A 45 50 48 59 52 |
| 20221024 140210.192 CONNECT ===> ZEPHYR 10 12 00 04 4D 51 54 54 04 02 00 3C 00 06 5A 45 50 48 59 52 |
| 20221024 140210.192 CONNACK <=== ZEPHYR 20 02 00 00 |
| 20221024 140210.192 CONNACK ---> ZEPHYR 03 05 00 |
| |
| 20221024 140210.643 SUBSCRIBE 0001 <--- ZEPHYR 0C 12 00 00 01 2F 6E 75 6D 62 65 72 |
| 20221024 140210.648 SUBSCRIBE 0001 ===> ZEPHYR 82 0C 00 01 00 07 2F 6E 75 6D 62 65 72 00 |
| 20221024 140210.660 SUBACK 0001 <=== ZEPHYR 90 03 00 01 00 |
| 20221024 140210.661 SUBACK 0001 ---> ZEPHYR 08 13 00 00 0D 00 01 00 |
| |
| 20221024 140220.338 REGISTER 0002 <--- ZEPHYR 0D 0A 00 00 00 02 2F 75 70 74 69 6D 65 |
| 20221024 140220.348 REGACK 0002 ---> ZEPHYR 07 0B 00 0E 00 02 00 |
| |
| 20221024 140220.848 PUBLISH <--- ZEPHYR 0C 0C 00 00 0E 00 00 31 30 32 30 30 |
| 20221024 140220.850 PUBLISH ===> ZEPHYR 30 0E 00 07 2F 75 70 74 69 6D 65 31 30 32 30 30 |
| |
| 20221024 140230.539 PUBLISH <--- ZEPHYR 0C 0C 00 00 0E 00 00 32 30 34 30 30 |
| 20221024 140230.542 PUBLISH ===> ZEPHYR 30 0E 00 07 2F 75 70 74 69 6D 65 32 30 34 30 30 |
