My MDT LED Controller for RGBW (KNX bus) supports color settings via an RGBW 6 byte color object in DPT 251.600, but I failed to address this DPT in the KNX binding. Instead, I was forced to use the RGB 3 byte color object in DPT 232.600 which works fine.
Therefore, the RGBW functionality is split into two distinct parts that are accessible via OpenHAB:
- RGB with a colorpicker to select the color and a dimmer to adjust the brightness, and
- Tunable White with a slider to select the color temperature (addressing all four channels RGBW) and a dimmer to adjust the brightness.
This setup basically works. When I start using the RGB functionality and select later onwards a particular color temperature for Tunable White, all four channels are correctly modified to reflect the newly selected color temperature and the colored light turns to white light according to the chosen color temperature. Fine.
But the other way round causes problems: When I activate Tunable White first and then adjust the color with the color picker, the separate White channel remains untouched, as the colorpicker only adjusts RGB nd not the separate W channel. Due to the fact that the White channel has a much brighter intensity, the RGB adjustments are not visible very well.
When adjusting the color via the colorpicker, I would like to automatically switch off the White channel. Now I wonder how to achieve this. The rule may not react on any change on the RGB channels, as the RGB channels are also modified when changing the color temperature for white light. In such a case, the separate White channel needs to remain on.
I would only like to switch off the separate White channel, if the colorpicker is used within OpenHAB.
As I am an absolute beginner with regard to rules, I have no idea how to start. OpenHAB 3 is up and running, as well as JSR223 with Jython and the helper libraries. Furthermore, I am not even sure whether my identified solution is an appropriate choice…