What version of Qt do I need for MQTTv5 support?

James Mark Chan

Can someone advise what version of Qt I need to use MQTTv5 client? Can a mqtt v3 client be used with an mqtt v5 server? Thanks in advance.

We are currently using qt v5.15.2

jsulm

@James-Mark-Chan It's documented: https://doc.qt.io/QtMQTT/index.html
"The supported versions are MQTT 3.1, MQTT 3.1.1, and MQTT 5.0"
Also consider this: "Note: Qt MQTT is part of the Qt for Automation offering and not Qt."

James Mark Chan

@jsulm said in What version of Qt do I need for MQTTv5 support?:

Qt for Automation offering

@jsulm Would you know if Qt for Automation offering is available in opensource / lgpl usage?

JoeCFD

Pre-built Qt for Automation installation packages are available under a commercial license. Open source developers can build their own binaries from the sources that are available under the GNU General Public License version 3 (GPLv3). Further, Qt OPC UA can be built with the GNU Lesser General Public License (LGPLv3) license, as long as the open62541 backend is used.

https://doc.qt.io/QtForAutomation/qtautomation-install.html

Qt MQTT is available under commercial licenses from The Qt Company. In addition, it is available under the GNU General Public License, version 3.
https://doc.qt.io/QtMQTT/index.html

JoeCFD

MQTT can be used without QtMQTT. However, you have to come up with an interface.