History

Marius Vikhammer 9c051965d2 MQTT: update default broker URL for examples The MQTT broker URL used as default in the examples has ceased operation. All examples and documention have been updated to point to the new domain mqtt.eclipse.org. This also required an update of the python example test scripts to use TLS 1.2		2019-11-06 01:26:48 +00:00
..
main	MQTT: update default broker URL for examples	2019-11-06 01:26:48 +00:00
CMakeLists.txt	MQTT: Integrate esp-mqtt library into idf	2018-09-12 08:00:59 +02:00
Makefile	MQTT: Integrate esp-mqtt library into idf	2018-09-12 08:00:59 +02:00
mqtt_tcp_example_test.py	mqtt: example tests refactored to provide descriptive failures, addapted to python23, removed workarround for launching without mqtt-paho package	2018-11-01 09:04:09 +01:00
README.md	MQTT: Integrate esp-mqtt library into idf	2018-09-12 08:00:59 +02:00
sdkconfig.ci	ci, examples: use sdkconfig.ci as an extra defaults file, if present	2019-01-22 10:15:10 +01:00

README.md

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 make menuconfig (using mqtt tcp transport) and as a demonstration subscribes/unsubscribes and send a message on certain topic. 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.

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

make menuconfig

Set serial port under Serial Flasher Options.
Set ssid and password for the board to connect to AP.

Build and Flash

Build the project and flash it to the board, then run monitor tool to view serial output:

make -j4 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 (3714) event: sta ip: 192.168.0.139, mask: 255.255.255.0, gw: 192.168.0.2
I (3714) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
I (3964) MQTT_CLIENT: Sending MQTT CONNECT message, type: 1, id: 0000
I (4164) MQTT_EXAMPLE: MQTT_EVENT_CONNECTED
I (4174) MQTT_EXAMPLE: sent publish successful, msg_id=41464
I (4174) MQTT_EXAMPLE: sent subscribe successful, msg_id=17886
I (4174) MQTT_EXAMPLE: sent subscribe successful, msg_id=42970
I (4184) MQTT_EXAMPLE: sent unsubscribe successful, msg_id=50241
I (4314) MQTT_EXAMPLE: MQTT_EVENT_PUBLISHED, msg_id=41464
I (4484) MQTT_EXAMPLE: MQTT_EVENT_SUBSCRIBED, msg_id=17886
I (4484) MQTT_EXAMPLE: sent publish successful, msg_id=0
I (4684) MQTT_EXAMPLE: MQTT_EVENT_SUBSCRIBED, msg_id=42970
I (4684) MQTT_EXAMPLE: sent publish successful, msg_id=0
I (4884) MQTT_CLIENT: deliver_publish, message_length_read=19, message_length=19
I (4884) MQTT_EXAMPLE: MQTT_EVENT_DATA
TOPIC=/topic/qos0
DATA=data
I (5194) MQTT_CLIENT: deliver_publish, message_length_read=19, message_length=19
I (5194) MQTT_EXAMPLE: MQTT_EVENT_DATA
TOPIC=/topic/qos0
DATA=data