ESP32 / Crossbar.io MQTT Bridge example

[oberstet]

A plain C code example using the STM32 SDK: a MQTT client that connects via MQTT/TLS to the MQTT Bridge of Crossbar.io to publish WAMP events and subscribe to WAMP topics.

This example does not use AutobahnC (for full WAMP), but uses a standard MQTT embedded client library to talk MQTT with Crossbar.io.

The example should live under: /device/esp32/components/mqtt_bridge_client.

This example is the ESP32 flavor of #4.

The example should be based on

• FreeRTOS
• lwIP
• mbedTLS
• Paho Embedded MQTT C/C++ Client

For the latter, see:

• https://eclipse.org/paho/clients/c/embedded/
• https://github.com/eclipse/paho.mqtt.embedded-c
• https://github.com/eclipse/paho.mqtt.embedded-c/blob/master/MQTTClient-C/samples/FreeRTOS/MQTTEcho.c
• https://developer.mbed.org/teams/mqtt/code/HelloMQTT/

[oberstet]

CB docs:

• http://crossbar.io/docs/MQTT-Broker/
• https://github.com/crossbario/crossbar-examples/tree/master/mqtt