NFC and Hoermann garage door drives

Hi everyone,

I’m having problems to make use of the NFC-functionality on the (android-) app and I’m unsure whether I’m simply unable to find a workaround, or it is worth to make an improvement sugggestion…

I would like to use an MFC-tag attached to my garage to have the door openend an closed each time I touch the tag with my mobile.
The garage door is driven by an Hoermann-KNX gateway. Unfortunately, the gateway’s implementation is a bit rudementary compared to other items
of this class (like rollershutters or dimmers).
Typically, the knx-application of such an actor provides several objects to alter a thing’s state:

  • UP/DOWN (to open or close a rollershutter/door)
  • MOVE/STOP (to move the rollershuttter/door by an increment or stop a movement)
  • POSITION (to set the opening/closing of a rollershutter/door to a given percentage)

Unfortunately, the Hoermann KNX-gateway lacks of the POSITION-object, which limits the usability of the NFC-functions on the app:

Obviously, it is impossible to set the absolute position of the door, but also the “toggle” option is affected:
when triggering this function with an NFC-tag, the openhab-app reports a message, suggesting that the item state is set to a position value of either 100% or 0% percent (depending on the previous state), opposed to set the item’s state UP or DOWN…

I’m aware that in most cases, this is just a tiny detail. In this case, however, the toggle-option is a non-working option, too, as no POSITION object is available to facilitate the command…

Given the fact, that I don’t really want to glue two different NFC-tags on to my garage (for UP and DOWN), does anyone have an idea how to handle this problem?
Considerations could also be given to changing the app’s nfc-toggle-implementation…

Thanks for your comments,

From p 20. Object 14 - this do you try to find?

Thanks for your note!

Unfortunately, the mentioned object is read-only!

On a side note: this object seems to be implemented much better than in previous versions of the gateway, the description of object 14 is incorrect:
while the door is moving, the object sends position reports continuously (between 0% and 100%)
One could setup a rule, to trigger a specific opening value.


So I misunderstood your problem.

As I understand, NFC tag generate % instead 1 and 0 command. NFC tag is connect to knx? Or from OH?

I use the openHAB-app (android) to write a toggle-command on the NFC-tag
When I check the data written to the tag, using a (random) NFC-tag reader, I find an openhab://- URL that calls my rollershutter-item with a toggle-command.
From the URL, you cannot tell what mechanism is triggered internally: no percentage or boolean value is passed to the app.

I can store a (boolean) UP or DOWN command on the tag - no problem - works as expected. It’s just the TOGGLE-command that doesn’t toggle :wink:

NFC-tag send command to OH → OH send command to rollershutter by knx bridge. Am I right?
Check object 6 in manual.

1-bit object to control the drive with a pulse sequence. With each telegram received,
the next state is adopted: Open - Stop - Close - Stop.

Yes - basically you are right.

Number six is only available, if drive movement parameter is set to open/stop/close. However, I’m making use of mode open/close (objects 1 & 2).
Apart from other implications in my house, I’m not sure whether a pulsed mode would be helpful concerning the NFC matter:
when programming an NFC-tag for a rollershutter item with the openHAB-app, you are offered a set of different actions/command alternatives: among them are “OPEN”, “CLOSE”, “TOGGLE”, “10%”, “20%” and a couple more, I cant remember right now.
To make use of object no. 6, you would need some kind of pulsed action. Something like “OPEN–>CLOSED” or vice versa, which is not offered as an command option (no suprise, though…).

I think the KNX-gateway is not a good starting point to solve my problem.
Most likely I will have to implement a kind of “helper item”, which is only controlled by the openHAB-app and triggers a rule, which -in turn- implements the required “toggle” for object 1 (open/close)…
But this is a kind of implementation of hell :wink:

With object 6 send command to KNX can be always 1 (“CLOSE” - depending from your setup). No need to solve toggle problem.
Other way - you get any signal from NFC tag to OH and make easy rule. If status of the gate close - send open, else - send close. Status open/close you can get from your rollershutter from 11 or 12 object.

Yup, apparently I didn’t read the object description properly: any telegram sent to object 6 is sufficient to trigger a movement. So it could be both - OPEN or CLOSE.

Thanks for sharing your ideas and helping out. For the time being, I will go with the “helper item” and setup a rule.
Nevertheless, it might be worth reconsidering the app’s behavior of setting the item’s status to 100% and 0%, respectively, when a “toggle”-command is requested.

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You can put your rollershuter in OH like switch object (use only for open-close action).

The app doesn’t know that the Item doesn’t accept 0% and 100%, so I don’t see a way to “fix” this issue in the app. You could add a switch and a rule that reacts on sending ON to this item.

Thanks for commenting,

this is exactly what I ended up doing… .
I created a switch “helper item”, which is not linked to a channel but triggers a rule on an item update. The rule itself takes care of opening and closing the rollershutter item.

Concerning the app - probably it’s not worth the effort implementing a “fix”, but one feasible approach could be offering another option for rollershutter items that explicitly allows toggeling [UP/DOWN] in addition to [0%/100%].

I wonder whether there would be any downside to using OPEN/CLOSE instead of 0/100 for toggling a roller shutter? Are there any roller shutters that can’t deal with OPEN/CLOSE?