APNT-120 - Motion Activated Light with Light Level sensor

This application note shows how to Associate two Z-Wave devices and use them to control a motion activated light that automatically turns On for a predefined period when motion is detected and the ambient light level is below a set threshold level.

Project Aim

The aim of this project is to automatically control a light:

Light turns on when motion is detected
Light stays On for 60 seconds after the last motion is detected
This system only works when the ambient light level is below a particular level (dusk)
Directly Associate the motion sensor with the light control so that it does not need the Z-Wave Central controller to control the lighting

Components

For this project I used a Z-Wave system comprising of:

Fibaro Dimmer 2 module - used to control the light via Z-Wave
Fibaro FGMS001 Motion Sensor GEN5 - used to sense motion, provide the Off delay and sense the light level
Vera Secure - central Z-Wave controller

Z-Wave Devices

The Fibaro Motion Sensor GEN5 was chosen as it includes a motion sensor, a light sensor that can be used to stop the detector sending commands until the ambient light level is below or above a defined threshold, and it includes a variable delay that will send an Off command to the Fibaro after a preset time period.

In other words it has all we need to create this light control and if we associate it directly with the Fibaro Dimmer 2 module, we will not need to use the Vera controller for day-to-day control of the lighting.

Z-Wave Association

Before going further, it's probably good to have a quick word about Z-Wave Association.

In most Z-Wave applications we configure them so that the central controller (Vera in this case) handles all commands. So for this example the motion detector would send a signal to the controller and as a second step the controller would send a command to the Fibaro dimmer.

However this adds unnecessary steps which can make this communication take too long. By Associating the motion detector and dimmer, enables the motion detector to send signals directly to the dimmer without involving the controller. This saves time, reduces the complexity of the communication and the amount of airtime taken.

Further information is available in Z-Wave Groups, Scenes & Associations.

Configuring the Fibaro Motion Sensor GEN5

For this system to work correctly we need to set some of the Fibaro's parameters, these are set in Vera by going to the Device Options tab.

For full information on setting device configuration parameters in Vera take a look at Application Note 102.

6 - Motion alarm will be cancelled in the main controller and associated devices after the period of time set in this parameter. Any motion detected during the cancellation delay time countdown will result in the countdown being restarted.
8 – Determines the part of day in which the PIR sensor will be active - set to 2 for Night Only
9 – Defines the difference between night and day, in terms of light intensity - used in Parameter 8

Associations

Being a battery operated device you’ll have to make sure the Fibaro Motion Sensor GEN5 is awake to receive the configuration parameters:

Change Parameters
Click "Save Changes" in Vera
Go back and under the Advanced tab click “Configure node right now”
Triple-click the Fibaro Motion Sensor GEN5 B-Button
Wait for Vera to finish setting the configurations
Refresh the page

You can check if the parameter has been correctly saved by comparing Desired Value with Current Value.

Setting the Association

Associating the Fibaro Sensor with the Dimmer module is very straightforward:

Go to the Fibaro Motion Sensor GEN5 Device Options tab
In Associations enter 2 in Group ID - this is because the Fibaro sends its motion commands to Z-Wave Group 2
Click "Add Group"
Click "Set"
Choose the device you wish to associate the sensor with - in this example it is Device ID 32