mqttc MQTT-C Example

This is a simple MQTT publisher example using MQTT-C.

By default it publishes to the “test” topic and exits. Default behaviour including, host, port, topic, message and loop count can be changed through different arguments.

Plain TCP (no Mbed TLS)

To test: From the host start an MQTT broker and subscribe to the “test” topic. Here mosquitto is used:

mosquitto&
mosquitto_sub -t test

Make sure that mosquitto is not configured in local mode only.

From the nsh:

Launch the built-in app mqttc_pub specifying the host:

mqttc_pub -h HOST

The target will publish the message “test”.

TLS with Mbed TLS

To use TLS, enable Mbed TLS and MQTT-C with Mbed TLS in menuconfig (see mqttc MQTT-C library). The same mqttc_pub binary is built with TLS support; the default port becomes 8883. You can pass -c with a path to your broker CA certificate in PEM format.

For full configuration symbols, CLI options, and the separate mqttc_mbedtls_pub example, see mqttc MQTT-C library.