Automation of the Loxone Office – Access Control

Lucinda Wood
10th November 2011 in Backstage

A topic which many have been looking forward to hear more about: Simple access control with Loxone. We have now integrated the building access control, as well as access control to different offices and store rooms with the Loxone Miniserver. We discovered that there were more opportunities and possible features than we initially intended to implement.

Access control: The starting point

Only a few fortunate people had the privilege to be in possession of the much sought after front door key. If these few chosen ones all decided to have a lie in on the same day, and this has happened on several occasions, then the rest stood in front of closed doors and had to wait. As winter draws ever closer standing outside is a thought that no one cherishes.

Apart from the front door almost every room in the building has a lock with its own key as well. For insurance reasons all of these have to be locked overnight, hence the morning usually does not start with a cup of coffee but a scenic tour of the building to unlock all rooms.

Fortunately this is now a relict of the past! We no longer have even a single key…

Access control with the 1-Wire Extension & iButton

Access is now granted with devices known as iButtons. Nothing to do with Apple though. iButtons are small chips, the size of a coin cell. These carry a unique ID, which can be read by an iButton reader. You may have seen these before in POS (point of sale) applications, like tills in pubs. They are made for harsh environments and will survive anything that a normal key would, probably even more. To top it all an iButton, which can be used to replace multiple keys, costs less than having a single key cut!


iButton with unique ID in its clip (Type: iButton DS1990 F5 with black clip)

The data exchange between the iButton and the iButton reader uses the 1-wire protocol and hence the reader can be directly connected to the our 1-Wire Extension. ibutton-leser

iButton reader for connection to Loxone 1-Wire Extension (Type: DS9092L+ )

We installed an iButton reader next to the front door, as well as each internal door, and connected them to the Loxone 1-Wire Extension. The doors themselves we fitted with electric latches, deadbolts, motorised locks or magnetic retainers as we saw fit. All of which are driven via the relays on the Miniserver.


Installation of iButton reader next to internal door. This door uses an electric latch.

Every employee now has their own iButton, which grants them access to the building and into certain rooms within. The iButton ID can be learned via Loxone Configuration software in the same manner as other 1-wire sensors, or you can type the serial number of the iButton in manually.

Once the iButton is pressed onto the reader, it will read the iButton ID and transmit it to the 1-Wire Extension. In Loxone Configuration Software individual iButton appear as digital inputs and hence can be used for more than just opening doors, like lighting, sockets, etc.

More than just unlocking the door

Though we have successfully installed a keyless entry system we are far from done! The beauty of a fully integrated system like Loxone is that a device intended for one task, can be used for so much more! So we are not simply replacing keys for the sake of it.

Here are just three examples that show what else you can accomplish with a little imagination and your Miniserver:

Access logging and tracking

As the Miniserver is already controlling the access, why not use the same information for access logging and tracking. Since every iButton has a unique ID we can not only log that someone entered the store room or returned to the office after hours, but also know who. This information can be written to a log file for later review, but may also be visualised on the user interface with the Tracker. Giving you the possibility of live monitoring.

Turn on lights and PC when unlocking the door

Since the iButtons simply appear as a digital input on the UI, they can be used for many other control tasks as we previously alluded to. So here a simple scenario of things that happen when Florian enters the building in the morning:

  • If the burglar alarm is still armed it gets disarmed
  • The lights in our windowless entrance hall get switched on.
  • The light in the marketing office is turned on, if it is not yet light outside.
  • The coffee machine is turned on (by switching its socket)
  • Florian’s PC boots (via Wake-On-LAN)

There is nothing that stops you from allowing your imagination free reign. Have a play and share with others on the forum what you have come up with.

Monitoring of windows and bad weather warning

Depending on the model, the iButton reader is fitted with an LED. Ours have got a green and a red LED built in. These can be used in many ways to provide some feedback. Here is what we have done with them.

  • The default behaviour on our iButton readers we setup so that the green LED is lit. Matching the Loxone colour scheme 😉
  • If however a window is open, the LED of the iButton reader lights up red to remind you to close the window before leaving the office.
  • As a little extra we also added a weather forecast function: If rain is forecast the LEDs will flash red.


iButton wire red LED on to indicate open windows

We implemented the window monitoring with the wireless EnOcean window contacts to avoid having to pull extra cables.

The LEDs of the iButton are powered directly via the analogue outputs of the Miniserver or Extension. This is possible as they require less than 20 mA at 2V, which is within the specification of the analogue outputs.

Simple to implement: All on a single configuration page

I have written a rather long blog post here and explained quite a few features that we implemented using our iButtons, but please do not be fooled into thinking that this takes pages over pages of configuration or scripts. Given little practice everything I described here can be implemented within a few minutes. Even better, all the configuration fits on one page!


Configuration of the access control, tracking and LED feedback.

Please feel free to not just take a look at the picture of the configuration, but also download the configuration file to test things for yourself.

I look forward to your feedback and thoughts on other features that can be implemented with an iButton, post them here as comments or on the forum.