Once a broker URL has been entered, it can be conveniently stored persistently in a list and later, if required, simply be selected from the list and selected for an automatic connection. The current status of the connection is constantly displayed by a flashing radio button. The connection can be reestablished manually on request via a button or menu.
The app can also be used to publish data on any topic of the connected broker. With which "QOS" and whether with or without "retained" can be specified.
In addition, you can select the received data of a specific subscribed topic directly in the list view, change it and publish it back to the broker.
Subtopics can also be included when subscribing using a wildcard (/#).
The data received for the subscribed topic and displayed in a list (ArrayList/ListView), including the associated topic name, can also be exported to a .txt file on an SD card. The name of this file is generated from the current time stamp. The files are saved in the /sdcard/MqttControl folder. To do this, the external memory must be available and the release for this memory access must be released.