Wiesemann & Theis GmbH

Networking, sensors and interface technology for industry, office and IT

Application example for the Web-IO Digital

Control Web-IO Digital via MQTT using a smartphone

Switch consumers in the local network over the network, barrier-free from the smartphone

Until now triggering switching actions in your own home remotely has been cumbersome. Either the home firewall had to be opened up and configured, or the services of a home automation provider including their cloud access had to be employed

Remote control with MQTT

Now there is an alternative with the Web-IO 4.0 Digital models used together with MQTT. In MQTT protocol communication between controlling app and the switching Web-IO is not direct, but rather through any desired broker in the internet. Both communication partners connect from the local network to the broker over the internet. This connecting direction is permitted by most firewalls.

Set up broker access

There are numerous providers of free broker services. In the example shown we have chosen the broker from HiveMQ.

On the web page https://hivemq.com you can click in the "Hive MQ Cloud for free" area on "Get started now!". Use "Sign Up Now" to begin configuring access. Here you also provide a user name and password for access.

Set up the Web-IO for switching via MQTT



Log in to the web interface of the Web-IO as administrator and in the menu tree select Communication paths >> MQTT. Here you can assign the access data for the MQTT broker and enable Publish and Subscribe with W&T standard topics.

Configuring Web-IO

Install and configure app for MQTT

Among the numerous MQTT apps available for smartphones with the Android operating system we have decided on the free MQTT Dash app. MQTT Dash can be easily downloaded and installed from the Google Playstore.

After starting the app you can tap on the "+" symbol at upper right in the display to add an MQTT broker. In the resulting view you must enter the access data. Tapping on the diskette symbol saves the broker configuration and generates a corresponding button.

Screenshot Smartphone, MQTT-Dash and Web-IO   Screenshot Smartphone, MQTT-Dash and Web-IO   Screenshot Smartphone, MQTT-Dash and Web-IO

Tapping on the Broker button takes you to the IO area. Here you can use the "+" symbol to add display fields and control elements for the needed inputs and outputs. For a status display only select "Text" type. TO control your output, select Switch/button type.

As topics you can enter the standard topics of the Web-IO.

Smartphone, MQTT-Dash and Web-IO   Smartphone, MQTT-Dash and Web-IO   Smartphone, MQTT-Dash and Web-IO

By adding additional topics, for example a Web-Thermohygrometer, you can also of course monitor other values and information such as temperature and relative humidity.

An iPhone can of course also be used with MQTT for switching and monitoring.