# KNX light switch seems to work but it doesn't
**URL:** https://community.homey.app/t/knx-light-switch-seems-to-work-but-it-doesnt/54991
**Category:** Devices
**Created:** [November 17, 2021, 5:58pm UTC](https://community.homey.app/t/knx-light-switch-seems-to-work-but-it-doesnt/54991 "2021-11-17T17:58:05Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Lenn](https://community.homey.app/u/Lenn)
#### Post date: [November 17, 2021, 5:58pm UTC](https://community.homey.app/t/knx-light-switch-seems-to-work-but-it-doesnt/54991/1 "2021-11-17T17:58:05Z")
Hi,
I got my Homey Pro a few days ago, and now I’m trying to integrate my KNX devices.
The electrician didn’t give me the project file and I couldn’t contact him 😕
A few month ago, I tried to integrate the devices with openhab and homeassistant without too much success, but I could get most of the groupadresses.
I tried to add several devices, but the result is the same :
When I try to switch a light, nothing happens in “real”, but on my touch screen (configured by the electrian), it “works”.
If I switch the light with the wallbutton, I see it change on homey.
So it seems the groupadresses are indeed correct… but something is not correct?
Thanks for reading, and sorry for the long explanation 🙂
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### Author:  [@Lenn](https://community.homey.app/u/Lenn)
#### Post date: [November 19, 2021, 12:53pm UTC](https://community.homey.app/t/knx-light-switch-seems-to-work-but-it-doesnt/54991/2 "2021-11-19T12:53:09Z")
Ok, I found myself the problem :
As I got the groupadresses “watching” the bus, groupadresses of the lights themselves and those of the switches were mixed together.
After some testing, I managed to found which is which, and it starts to work 🙂