KNX and Hue



I want to control my dimmable Hue lamps with KNX switches.

On/off is already working by combining the two bindings for the switch item:

Switch Lamp "Lamp" { channel="hue:0100:55555:2:brightness", knx="1/1/22" }

The group address 1/1/22 is linked to the “switch” functionality of the KNX switch. I found this somewhere here in the forum.

But dimming is not working this way:

Dimmer Lamp_Dimmer "Lamp" { channel="hue:0100:55555:2:brightness", knx="1/1/23" }

1/2/23 is the group address that is bound to the “dimming” functionality of the KNX switch. I assume that the problem is “current dimming value” vs. “new dimming value”.

Do I have to create a rule in order to dim my Hue lamps with KNX switches? Or is there another, smarter way?

You have to define your KNX dimmer a bit differently. Please check the binding documentation example section at

Thank you for this hint.

I had to modify the items-definition:

Switch Lamp "Lamp" { channel="hue:0100:55555:2:brightness", knx="1/1/22" }
Dimmer Lamp_Dimmer "Lamp" { channel="hue:0100:55555:2:brightness", knx="1/1/22, 1/1/23" }

Furthermore I had to modify my KNX switch in order to send dimming telegrams repeatedly instead of start and stop telegrams.

Which KNX switch do you have? I have the MDT glass switch and unfortunately i can’t change the way the messages are sent.
The dimming to dark is aborted after a short reduction of the brightness. As long as i keep the button pressed the brightness keeps its value but as soon as i release the button the brightness gets set to 100% again.
I dont understand who request the 100% again…

However if i configure the glass switch to send absolute values there is no problem and the brightness keeps constant.

I have a Gira Tastsensor 3. The switch is set to relative dimming. But I had to change its behavior:

The switch is sending dimming telegrams every 200 ms, as long as the button is pressed. I had to reduce the dimming steps down to 6%. With these changes I am able to dim the Hue lamps nice and smoothly.

As far as I remember, the default dimming behavior is to send a start and a stop telegram. That did not work with the hue lamps.

I could solve it by applying a “ss” to the dimming message. See for details.

Dimmer eg_buero_glastaster_hue "Hue Buero" { channel="hue:0100:1234:2:brightness", knx="1/0/2, 1/0/3ss, 1/0/4" }

Glad that it works for you now.

I never heard of this “ss” suffix. Thank you for sharing this information.

Hi Andi,

this is a old topic :slight_smile:
I am using Openhab 3 to control a Dimmer (Philips HUE) with an MDT Glastaster (KNX).
I´m using a dimmer Control Channel with a rule. This works, but it is not perfect.

Does the KNX Binding 3.0 support Start/Stop Commands by adding ss at the end of the Group Adress? {knx=“3.007:2/0/1ss”}

Thanks for your help.

Regards Pascal

Hello Pascal,

as I am not running OH3 I can’t tell you.
Perhaps you can just give it a try for example with an OH3 docker container (if they already exist)?