ESP-MQTT ======== Overview -------- ESP-MQTT is an implementation of MQTT protocol client (MQTT is a lightweight publish/subscribe messaging protocol). Features -------- * supports MQTT over TCP, SSL with mbedtls, MQTT over Websocket, MQTT over Websocket Secure. * Easy to setup with URI * Multiple instances (Multiple clients in one application) * Support subscribing, publishing, authentication, will messages, keep alive pings and all 3 QoS levels (it should be a fully functional client). Application Example ------------------- * :example:`protocols/mqtt/tcp`: MQTT over tcp, defalut port 1883 * :example:`protocols/mqtt/ssl`: MQTT over tcp, defalut port 8883 * :example:`protocols/mqtt/ws`: MQTT over Websocket, defalut port 80 * :example:`protocols/mqtt/wss`: MQTT over Websocket Secure, defalut port 443 Configuration ------------- URI ^^^ - Curently support ``mqtt``, ``mqtts``, ``ws``, ``wss`` schemes - MQTT over TCP samples: - ``mqtt://iot.eclipse.org``: MQTT over TCP, default port 1883: - ``mqtt://iot.eclipse.org:1884`` MQTT over TCP, port 1884: - ``mqtt://username:password@iot.eclipse.org:1884`` MQTT over TCP, port 1884, with username and password - MQTT over SSL samples: - ``mqtts://iot.eclipse.org``: MQTT over SSL, port 8883 - ``mqtts://iot.eclipse.org:8884``: MQTT over SSL, port 8884 - MQTT over Websocket samples: - ``ws://iot.eclipse.org:80/ws`` - MQTT over Websocket Secure samples: - ``wss://iot.eclipse.org:443/ws`` - Minimal configurations: .. code:: c const esp_mqtt_client_config_t mqtt_cfg = { .uri = "mqtt://iot.eclipse.org", .event_handle = mqtt_event_handler, // .user_context = (void *)your_context }; - If there are any options related to the URI in ``esp_mqtt_client_config_t``, the option defined by the URI will be overridden. Sample: .. code:: c const esp_mqtt_client_config_t mqtt_cfg = { .uri = "mqtt://iot.eclipse.org:1234", .event_handle = mqtt_event_handler, .port = 4567, }; //MQTT client will connect to iot.eclipse.org using port 4567 SSL ^^^ - Get certificate from server, example: ``iot.eclipse.org`` ``openssl s_client -showcerts -connect iot.eclipse.org:8883 /dev/null|openssl x509 -outform PEM >iot_eclipse_org.pem`` - Check the sample application: ``examples/mqtt_ssl`` - Configuration: .. code:: cpp const esp_mqtt_client_config_t mqtt_cfg = { .uri = "mqtts://iot.eclipse.org:8883", .event_handle = mqtt_event_handler, .cert_pem = (const char *)iot_eclipse_org_pem_start, }; For more options on ``esp_mqtt_client_config_t``, please refer to API reference below Change settings in ``menuconfig`` ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ :: make menuconfig -> Component config -> ESP-MQTT Configuration - :envvar:`CONFIG_MQTT_PROTOCOL_311`: Enables 3.1.1 version of MQTT protocol - :envvar:`MQTT_TRANSPORT_%TRANSPORT%`: Enables specific MQTT transport layer, such as SSL, WEBSOCKET, WEBSOCKET_SECURE - :envvar:`MQTT_CUSTOM_OUTBOX`: Disables default implementation of mqtt_outbox, so a specific implementaion can be supplied API Reference ------------- .. include:: /_build/inc/mqtt_client.inc