MQTT is a publish/subscribe messaging transport protocol for M2M communications. It runs over TCP or TLS and is supported by many IoT platforms.
MQTT in Contiki-NG
Contiki-NG features a client implementation of MQTT version 3.1. The implementation supports MQTT QoS levels 0 and 1 and allows a Contiki-NG MQTT client to subscribe with and publish to an MQTT broker.
The MQTT engine is implemented in
os/net/app-layer/mqtt/mqtt.[ch]. The implementation does not currently offer any configuration options.
The MQTT client engine has been tested against the Mosquitto MQTT broker, as well as against IBM’s Quickstart / Watson IoT Platform.
Visit tutorial:mqtt for an example on how to use the MQTT client on your device.
The implementation does not support MQTT QoS 2.
The implementation does not support reception of publish messages with QoS 1.
The implementation does not support MQTT over TLS.