1# ESP-MQTT MQTT over Websocket
2
3(See the README.md file in the upper level 'examples' directory for more information about examples.)
4
5This example connects to the broker mqtt.eclipseprojects.io over web sockets as a demonstration subscribes/unsubscribes and send a message on certain topic.
6(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))
7
8It uses ESP-MQTT library which implements mqtt client to connect to mqtt broker.
9
10## How to use example
11
12### Hardware Required
13
14This example can be executed on any ESP32 board, the only required interface is WiFi and connection to internet.
15
16### Configure the project
17
18* Open the project configuration menu (`idf.py menuconfig`)
19* 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.
20* When using Make build system, set `Default serial port` under `Serial flasher config`.
21
22### Build and Flash
23
24Build the project and flash it to the board, then run monitor tool to view serial output:
25
26```
27idf.py -p PORT flash monitor
28```
29
30(To exit the serial monitor, type ``Ctrl-]``.)
31
32See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
33
34## Example Output
35
36```
37I (3714) event: sta ip: 192.168.0.139, mask: 255.255.255.0, gw: 192.168.0.2
38I (3714) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
39I (3964) MQTT_CLIENT: Sending MQTT CONNECT message, type: 1, id: 0000
40I (4164) MQTTWS_EXAMPLE: MQTT_EVENT_CONNECTED
41I (4174) MQTTWS_EXAMPLE: sent publish successful, msg_id=41464
42I (4174) MQTTWS_EXAMPLE: sent subscribe successful, msg_id=17886
43I (4174) MQTTWS_EXAMPLE: sent subscribe successful, msg_id=42970
44I (4184) MQTTWS_EXAMPLE: sent unsubscribe successful, msg_id=50241
45I (4314) MQTTWS_EXAMPLE: MQTT_EVENT_PUBLISHED, msg_id=41464
46I (4484) MQTTWS_EXAMPLE: MQTT_EVENT_SUBSCRIBED, msg_id=17886
47I (4484) MQTTWS_EXAMPLE: sent publish successful, msg_id=0
48I (4684) MQTTWS_EXAMPLE: MQTT_EVENT_SUBSCRIBED, msg_id=42970
49I (4684) MQTTWS_EXAMPLE: sent publish successful, msg_id=0
50I (4884) MQTT_CLIENT: deliver_publish, message_length_read=19, message_length=19
51I (4884) MQTTWS_EXAMPLE: MQTT_EVENT_DATA
52TOPIC=/topic/qos0
53DATA=data
54I (5194) MQTT_CLIENT: deliver_publish, message_length_read=19, message_length=19
55I (5194) MQTTWS_EXAMPLE: MQTT_EVENT_DATA
56TOPIC=/topic/qos0
57DATA=data
58```
59
60