HELP: Motion Sensor Rule

[rlkoshak (Rich Koshak)]

See the following for determining when it is night.

Automation/Orchestration Design Patterns

RLK back with another Design Pattern to add to the list. Time Of Day Triggers The Problem: Many of us have rules that we want to only execute or behave differently during certain time periods of the day. As our rules grow there is the potential that more and more parts of the system will need to have this capability (e.g. lighting, HVAC, blinds, etc). Sometimes the times that define a period are fixed (e.g. 11pm) and others they are based on celestial events (e.g. sunset). This can result in …

Now that we know it is night we have a couple of challenges with a rule like this.

• How frequently does the motion detector go off? Do you truly only receive on event when you go past the detector and only one when you come back? Or do you receive multiple events in this case? I’ll assume it is only one but if it is multiple you will need to add some debouncing.

• The second challenge is we need to keep track of whether a given motion sensor event is the first or the second one in the sequence and do something different based on which it is.

So the over all approach would be something like the following:

Items:

Contact MotionSensor ...
Switch Light ...

// Create a Swtich to help us determine whether this is the first or second triggering of the MotionSensor
// This could also be implemented as a global var in the Rules file, I like to use Items because I can use
// restoreOnStartup which lets the rule support restarts more reliably and with fewer lines of code.
Switch MotionSensorFlag

Rule:

rule "MotionSensor triggered"
when
    Item MotionSensor received update
then
    if(TimeOfDay.state.toString == "Night") {
        // First MotionSensor trigger in the sequence
        // I use != ON so it works correctly in the case that MotionSensorFlag is Undefined
        if(MotionSensorFlag.state != ON) {
            Light.sendCommand(ON)
            MotionSensorFlag.sendCommand(ON)
        }

        // Second MotionSensor trigger in the sequence
        else {
            MotionSensorFlag.sendCommand(OFF)
            Thread::sleep(10000) // You could use a Timer but I think Thread::sleep results in simpler code and it works well here
            Light.sendCommand(OFF)
        }
    }
end

The above only works if you truly only receive one event from the MotionSensor on each pass. If not it will get a whole lot more complicated. Search the forum for “debounce” and you will see lots of examples of ways to deal with it though.

EDIT: Forgot to add the test for Night