Alexa provides a kind interface for thermostats working with a target temperature and optionally with upper and lower temperature boundaries. In my paticular case the thermostat is not controlled through specific temperature values but by power-levels. So there are 10 possible power-levels the thermostat can be set to (0-10). Furthermore the device should be queried for the current room temperature. My attempt was to provide a endpoint which implements the PercentageController-Interface to represent the 10 power-levels and the TemperatureSensor-Interface to display the current temperature. Voice interaction with this endpoint worked perfectly fine,but then I checked the graphic representation in the Alexa-App and saw, that the current Temperature was not displayed there. So am I right in the assumption that the value of the "displayCategories" field completely decides how the UI will stare like in the Alexa-App and you have no chance of adding anything to it? And why is displayCategories an array?
Source: amazon.com