Include Window contacts


My windows have integrated switches that indicate its status (open, closed). Currently there is no interface installed to analyze the status of the windows (so I only have the bare wires).

Do you have any recommendations for a window interface for approx. 15 windows? Of course it should be also compatible with openHAB…

Thank you!

Some more details on your windows would ber very welcome.

Guessing these are a leftover from a previous intruder alarm system? beware that there may be resistors in circuit i.e. not simple switches.

One way to reinvogorate them might be to install a new intruder alarm central unit, that openHAB can communicate with.

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Actually, these are new windows. As far as I am aware really only reed switches have been installed and the wires terminate in my cellar. I just had them installed without installing an alarm system yet.

A small PLC or a few ESP32 devices may work, depending on the distance and other electrical interference.

Any hints for a less DIY solution. At least with components already prebuild?



Thank you, you brought me on the right track: I found this as well, it explicitly mentions openHAB support (using SNMP):

I am not yet sure what to order.

Why could you not use a simple zwave door/window sensor? Most of them have connect for external sensors.

Yeh but not sixteen of them …

It would perhaps be possible to group the window switches in wiring, say by room, to reduce the I/O requirement.


to close the subject. I have now shot a NodeMCU from Ebay and connected my window sensors via an MCP23017 (Port Extender) via I2C.
The NodeMCU then simply sends a message via MQTT whether the contact is conducting or not.
In case someone has a similar problem, please just let me know, then I will gladly send the source code and hints for the cabling.


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