| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C6 | ESP32-S2 | ESP32-S3 | | ----------------- | ----- | -------- | -------- | -------- | -------- | -------- | # ESP-MQTT sample application (See the README.md file in the upper level 'examples' directory for more information about examples.) This example connects to the broker URI selected using `idf.py menuconfig` (using mqtt tcp transport) and as a demonstration subscribes/unsubscribes and send a message on certain topic. (Please note that the public broker is maintained by the community so may not be always available, for details please see this [disclaimer](https://iot.eclipse.org/getting-started/#sandboxes)) Note: If the URI equals `FROM_STDIN` then the broker address is read from stdin upon application startup (used for testing) It uses ESP-MQTT library which implements mqtt client to connect to mqtt broker with MQTT version 5. The more details about MQTT v5, please refer to [official website](https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html) ## How to use example ### Hardware Required This example can be executed on any ESP32 board, the only required interface is WiFi and connection to internet. ### Configure the project * Open the project configuration menu (`idf.py menuconfig`) * Configure Wi-Fi or Ethernet under "Example Connection Configuration" menu. See "Establishing Wi-Fi or Ethernet Connection" section in [examples/protocols/README.md](../../README.md) for more details. * MQTT v5 protocol (`CONFIG_MQTT_PROTOCOL_5`) under "ESP-MQTT Configurations" menu is enabled by `sdkconfig.defaults`. ### Build and Flash Build the project and flash it to the board, then run monitor tool to view serial output: ``` idf.py -p PORT flash monitor ``` (To exit the serial monitor, type ``Ctrl-]``.) See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects. ## Example Output ``` I (5119) esp_netif_handlers: example_connect: sta ip: 192.168.3.143, mask: 255.255.255.0, gw: 192.168.3.1 I (5119) example_connect: Got IPv4 event: Interface "example_connect: sta" address: 192.168.3.143 I (5619) example_connect: Got IPv6 event: Interface "example_connect: sta" address: fe80:0000:0000:0000:c64f:33ff:fe24:6645, type: ESP_IP6_ADDR_IS_LINK_LOCAL I (5619) example_connect: Connected to example_connect: sta I (5629) example_connect: - IPv4 address: 192.168.3.143 I (5629) example_connect: - IPv6 address: fe80:0000:0000:0000:c64f:33ff:fe24:6645, type: ESP_IP6_ADDR_IS_LINK_LOCAL I (5649) MQTT5_EXAMPLE: Other event id:7 W (6299) wifi:idx:0 (ifx:0, 34:29:12:43:c5:40), tid:7, ssn:0, winSize:64 I (7439) MQTT5_EXAMPLE: MQTT_EVENT_CONNECTED I (7439) MQTT5_EXAMPLE: sent publish successful, msg_id=53118 I (7439) MQTT5_EXAMPLE: sent subscribe successful, msg_id=41391 I (7439) MQTT5_EXAMPLE: sent subscribe successful, msg_id=13695 I (7449) MQTT5_EXAMPLE: sent unsubscribe successful, msg_id=55594 I (7649) mqtt5_client: MQTT_MSG_TYPE_PUBACK return code is -1 I (7649) MQTT5_EXAMPLE: MQTT_EVENT_PUBLISHED, msg_id=53118 I (8039) mqtt5_client: MQTT_MSG_TYPE_SUBACK return code is 0 I (8049) MQTT5_EXAMPLE: MQTT_EVENT_SUBSCRIBED, msg_id=41391 I (8049) MQTT5_EXAMPLE: sent publish successful, msg_id=0 I (8059) mqtt5_client: MQTT_MSG_TYPE_SUBACK return code is 2 I (8059) MQTT5_EXAMPLE: MQTT_EVENT_SUBSCRIBED, msg_id=13695 I (8069) MQTT5_EXAMPLE: sent publish successful, msg_id=0 I (8079) MQTT5_EXAMPLE: MQTT_EVENT_DATA I (8079) MQTT5_EXAMPLE: key is board, value is esp32 I (8079) MQTT5_EXAMPLE: key is u, value is user I (8089) MQTT5_EXAMPLE: key is p, value is password I (8089) MQTT5_EXAMPLE: payload_format_indicator is 1 I (8099) MQTT5_EXAMPLE: response_topic is /topic/test/response I (8109) MQTT5_EXAMPLE: correlation_data is 123456 I (8109) MQTT5_EXAMPLE: content_type is I (8119) MQTT5_EXAMPLE: TOPIC=/topic/qos1 I (8119) MQTT5_EXAMPLE: DATA=data_3 I (8129) mqtt5_client: MQTT_MSG_TYPE_UNSUBACK return code is 0 I (8129) MQTT5_EXAMPLE: MQTT_EVENT_UNSUBSCRIBED, msg_id=55594 I (8139) mqtt_client: Client asked to disconnect I (9159) MQTT5_EXAMPLE: MQTT_EVENT_DISCONNECTED ```