# KNX + Hue (RGB to HSV) Beginner

**URL:** <https://discourse.nodered.org/t/knx-hue-rgb-to-hsv-beginner/51340>\
**Category:** General\
**Created:** [21 September 2021 13:19 UTC](https://discourse.nodered.org/t/knx-hue-rgb-to-hsv-beginner/51340 "2021-09-21T13:19:15Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![overfl0w](https://avatars.discourse-cdn.com/v4/letter/o/e9a140/32.png) [@overfl0w](https://discourse.nodered.org/u/overfl0w)\
**Post date:** [21 September 2021 13:19 UTC](https://discourse.nodered.org/t/knx-hue-rgb-to-hsv-beginner/51340/1 "2021-09-21T13:19:15Z")

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Hello all,

I'm a complete NodeRed newbie and I'm facing a problem that I can't get solved on my own.

I have a KNX installation in my house and use switches from MDT. These have a color display and you can pass HSV values via a color selector.

I also have Phillips Hue lamps throughout the house. Now I would like to use the switch to set the colors of the Hue lamps. During my research I came across the following: [node-red-contrib-color-convert (node) - Node-RED](https://flows.nodered.org/node/node-red-contrib-color-convert)

Do any of you have experience with KNX + Hue + NR + MDT glass switch 2?

I am grateful for any help.  
Best regards

Maurice

 ![MDT_BEGT20W01_S](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/6/c/6c5dd798792bd97ba7d9a7b6a1855a359a062913.jpeg)

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**Author:** ![Christian-Me](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/christian-me/32/10774_2.png) [@Christian-Me](https://discourse.nodered.org/u/Christian-Me)\
**Post date:** [21 September 2021 16:12 UTC](https://discourse.nodered.org/t/knx-hue-rgb-to-hsv-beginner/51340/2 "2021-09-21T16:12:42Z")

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All I know about the hue and some zigbee bulbs is that the need CIE 1931 x,y,z or x,y values … some bridges (hard- or software do the conversion.

You/we have to know what you get fom your knx device and what your bulb expects

Perhaps the node-contrib-chroma node can help here too. Together with the node-contrib-ui-iro-color-picker they work for me wit various formats

> **[node-red-contrib-ui-iro-color-picker](https://flows.nodered.org/node/node-red-contrib-ui-iro-color-picker)**
>
> iro.js color picker for the Node-RED dashboard

> **[node-red-contrib-chroma](https://flows.nodered.org/node/node-red-contrib-chroma)**
>
> color conversion based on chroma.js

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<div class="post-metadata">

**Author:** ![overfl0w](https://avatars.discourse-cdn.com/v4/letter/o/e9a140/32.png) [@overfl0w](https://discourse.nodered.org/u/overfl0w)\
**Post date:** [21 September 2021 19:42 UTC](https://discourse.nodered.org/t/knx-hue-rgb-to-hsv-beginner/51340/3 "2021-09-21T19:42:29Z")

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thank you very much for your answer. i am really interested in this problem. gladly i will give all the details needed. only unfortunately i do not know how to find them out?

below are some screenshots from the ets:

Thanks in advance

 ![Screenshot_1](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/1/d/1d9d0606fea0b64d6282ec6537b31ff719930f7f.jpeg)

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<div class="post-metadata">

**Author:** ![Christian-Me](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/christian-me/32/10774_2.png) [@Christian-Me](https://discourse.nodered.org/u/Christian-Me)\
**Post date:** [21 September 2021 20:50 UTC](https://discourse.nodered.org/t/knx-hue-rgb-to-hsv-beginner/51340/4 "2021-09-21T20:50:36Z")

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Ok .. to avoid confusion you get your data from your adorable knx interface into node red and like to control a hue bulb (which I both do not own)  
1st you should place a debug node behind your output (knx node) to see what data you get. There is at least one knx node available in the palette manager.  
Then you have to determine what input your hue node expects (help page)  
The chroma node can then convert that. And with the color picker you can verify the input and output visually on the dashboard

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<div class="post-metadata">

**Author:** ![overfl0w](https://avatars.discourse-cdn.com/v4/letter/o/e9a140/32.png) [@overfl0w](https://discourse.nodered.org/u/overfl0w)\
**Post date:** [22 September 2021 06:24 UTC](https://discourse.nodered.org/t/knx-hue-rgb-to-hsv-beginner/51340/5 "2021-09-22T06:24:46Z")

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Good morning, thanks for the tutorial. As soon as I am home I will try the whole thing and tell what happens.

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**Author:** ![iiLaw](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/iilaw/32/14782_2.png) [@iiLaw](https://discourse.nodered.org/u/iiLaw)\
**Post date:** [22 September 2021 08:43 UTC](https://discourse.nodered.org/t/knx-hue-rgb-to-hsv-beginner/51340/6 "2021-09-22T08:43:59Z")

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[overfl0w](https://discourse.nodered.org/u/overfl0w) Hi if you haven't already used it I would recommend.

> **[node-red-contrib-knx-ultimate](https://flows.nodered.org/node/node-red-contrib-knx-ultimate)**
>
> Control your KNX intallation via Node-Red! Single Node KNX IN/OUT with optional ETS group address importer. Easy to use and highly configurable.

Looking at ETS the switch sends 0-255 value for R, G, B so you will need convert that Group Address values to HUE RGB. I think the KNX datatype is

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/3X/c/0/c06722298c7235d8301f972a016ef633cfbf0a1b.png)

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<div class="post-metadata">

**Author:** ![overfl0w](https://avatars.discourse-cdn.com/v4/letter/o/e9a140/32.png) [@overfl0w](https://discourse.nodered.org/u/overfl0w)\
**Post date:** [22 September 2021 11:31 UTC](https://discourse.nodered.org/t/knx-hue-rgb-to-hsv-beginner/51340/7 "2021-09-22T11:31:23Z")

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Great! Thank you so much for those informations. i will try and give you a feedback.  
greetings

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [21 November 2021 11:31 UTC](https://discourse.nodered.org/t/knx-hue-rgb-to-hsv-beginner/51340/8 "2021-11-21T11:31:46Z")

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