OVMS3-idf/examples/protocols/mqtt/wss/README.md
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

2.3 KiB

ESP-MQTT MQTT over WSS Sample application

(See the README.md file in the upper level 'examples' directory for more information about examples.)

This example connects to the broker mqtt.eclipse.org over secure websockets and as a demonstration subscribes/unsubscribes and send a message on certain topic.

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.

Note how to create a PEM certificate for mqtt.eclipse.org:

openssl s_client -showcerts -connect mqtt.eclipse.org:8883 </dev/null 2>/dev/null|openssl x509 -outform PEM >iot_eclipse_org.pem

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) MQTTWSS_EXAMPLE: MQTT_EVENT_CONNECTED
I (4174) MQTTWSS_EXAMPLE: sent publish successful, msg_id=41464
I (4174) MQTTWSS_EXAMPLE: sent subscribe successful, msg_id=17886
I (4174) MQTTWSS_EXAMPLE: sent subscribe successful, msg_id=42970
I (4184) MQTTWSS_EXAMPLE: sent unsubscribe successful, msg_id=50241
I (4314) MQTTWSS_EXAMPLE: MQTT_EVENT_PUBLISHED, msg_id=41464
I (4484) MQTTWSS_EXAMPLE: MQTT_EVENT_SUBSCRIBED, msg_id=17886
I (4484) MQTTWSS_EXAMPLE: sent publish successful, msg_id=0
I (4684) MQTTWSS_EXAMPLE: MQTT_EVENT_SUBSCRIBED, msg_id=42970
I (4684) MQTTWSS_EXAMPLE: sent publish successful, msg_id=0
I (4884) MQTT_CLIENT: deliver_publish, message_length_read=19, message_length=19
I (4884) MQTTWSS_EXAMPLE: MQTT_EVENT_DATA
TOPIC=/topic/qos0
DATA=data
I (5194) MQTT_CLIENT: deliver_publish, message_length_read=19, message_length=19
I (5194) MQTTWSS_EXAMPLE: MQTT_EVENT_DATA
TOPIC=/topic/qos0
DATA=data