Stairs

[pbj]

Apologies in advance, as I start to think more seriously about an install I'm no doubt going to have some daft questions... Rather than bothering Karam the whole time hopefully you good peole can help.

How do people handle peresence and stairs? I'm thinking of putting a sensor or two on a couple of staircases to help with presence detection (particularly as we have tread lights I'm guessing that I may want to treat them as a room on their own). It's going to be difficult to use PIRs because of the layout, so I was thinking of either a pressure mat or some sort of beam break sensor embedded in the wall. Any views on either of these, do pressure mats have longevity issues?

If I go for either pressure or beam break do I place a sensor at the top and bottom of the stairs to give cortex a clue (to cover both directions of travel)?

[chris_j_hunter]

good question (!) - we need to arrange something similar ... ie: switching-on things on the walls by the stairs only when people are on the stairs ... in our case, a push-button top & bottom might be OK, but something smarter & automatic would be much better ...

ATM, we've PLHs covering the lobbies top & bottom, and we're treating the lobbies as separate Rooms, joined by the stairs ... and a current issue is that the Motion detector in each lobby detects motion in both lobbies, leading to some confusion as to where people are & from where to where they're moving ...

we're not sure how exactly stairs are handled in Cortex - just a connection that's not a door, so always open, presumably, but there's the business of Floors, too ...

treating stairs as a room, with a door at each end, with a pressure-mat instead of a reed switch, say, sounds tempting - not sure, though how the business of Floors would be handled - ie: Stairs join Floors, as well as Rooms ...

hmm, lots of questions without answers !

[Paul_B]

I wonder if curtain type PIR would of any use? The following gives a good idea of how they work:

http://store.viewcare.co.uk/Clip_MCW.asp

Paul

[Viv]

The concept of the stairs is basically an open door.
There is little difference of the opening between a hall and landing (stairs or stair well) and a hall to lounge (open door).
If the hall is occupied and there is motion in the lounge then presence is transferred to the lounge.
Similarly if the hall is occupied and the landing senses motion then presence is transferred to the landing.

Care should be taken to have the hall PIR(s) detect someone coming down the stairs but not to see someone at the top of the stairs. This will ensure the hall lights come on before you reach the bottom.
Similarly, for the landing PIR(s) to detect someone at the top of the stairs but not walking at the foot of the stairs.

Cortex has an object to provide the logic for a beam sensor across a door opening. The output of the beam sensor is feed to a special input in the door object.
The stairs does not provide such logic but if anyone wants to make such a set-up of beam sensor across the stairs we will add this logic to the stairs.

Viv.

[westernm]

I would be very keen for this to be added, as our home is very open plan we are going to have to use the beam break approach quite a lot.

Mark

[Viv]

OK. The ability to connect the proximity detector to the stairs will be provided in release 25.2.18 when available.

Viv

[Paul_B]

Thanks Viv I think I will be using a beam sensor as well for the stairs. Our house has a U-shape staircase and a Golden Retriever who freely roams between downstaris and upstairs. I plan to cover the landing with a pet immune PIR, but I don't believe this would work in the hall because most pet immune PIRs assume the dog's height is below 1m. I'm thinking of putting a beam at the bottom of the stairs to sense presence

Paul

[Viv]

Just for clarity...

When a proximity sensor object is connected to a door object (and soon to be stairs) it has the effect of making the door considered impenetrable even if the door is open. Thus motion on both sides of the door will cause both rooms to be considered occupied. Because someone has not travelled through the door this would be correct.

When someone walks through the door the detector registers. Both rooms on either side of the door then have their occupancy reset to zero. The system then relies upon the motion sensor on the appropriate side of the door to register presence on the correct side.

If direction sensors are used (two beams which allow direction to be determined) the logic is slightly different. Again the door is considered impenetrable even if it is open. So presence can be detected and registered in both rooms at the same time. When someone passes through the door their direction is known. This then means the room which they left then becomes unoccupied and the room they entered into becomes occupied (if it was not already).

Viv

[pbj]

Thanks Viv, very useful.

One of the tricky stairs is from the bedrrom up to the ensuite (the stairs are open to the bedroom). At night I'd like the stair tread lights to come on when someone is close to or at the bottom of the stairs (to stop me falling down the stairs), I doubt that using the bedroom PIR will be a good plan because I don't want the stair lights coming on if one of us rolls over in bed!

I had imagined modelling the stairs as a room with a door at each end with stairs in it (to get the floor connection). I was hoping to put a pressure mat or beam break on the bottom tread and the top tread and connect these as door sensors.

However, if I've got the right end of the stick, this won't work as cortex will reset the presence in the "stairs room", but then there's no PIR to detect any other movement so the lights won't come on (unless I brew some other logic). I guess I could use a directional beam detector (or pressure mats on consecutive treads) at the top and bottom to link to the imaginary doors.

Having said all that... I think I might be better off having a pressure mat at top and bottom (they seem easy, cheap and very hidable!) and then using some logic with a T-flip flop!

[Viv]

You could connect the pressure pad (via a digital input) to the lights timer input.
The digital input can be made active over a particular time period.
The light will then turn on for defined period regardless of presence, lightlevel etc.

Viv

[Geps]

Looking at the stairs as a room idea...if you have a pressure mat on the top and bottom treads doesn't it all fall over when two people go upstairs but the one behind forgets something and turns back? You then have a "room" with 2/3 people in when realistically you only have 0/1.

I was thinking about this and decided you could use a rangefinder down the middle of the stairs. If the length is less than the length of the stairs then someone is on the stairs.

In the end though I've specced in a 'censored' PIR sensor look down the stairs so it only sees the stairs and not the landing.

Viv out of interest is there a recommended or known-to-work dual beam sensor that's available off the shelf?

[pbj]

Good point. Although in our case I think we'll be OK as the stairs only lead to the ensuite.

[chris_j_hunter]

we've looked for a beam breaker sensor - sounds easy, but all we've found have been expensive and/or far from compact / simple to install ...

this seems to offer a slightly different approach that avoids such issues - it comes in two versions :

http://www.oomlout.co.uk/infra-red-distance-sensor-w-cable-p-229.html

http://www.coolcomponents.co.uk/catalog/resources/GP2D12IRSENSOR/GP2Y0A21YK.pdf

the A-type gives a signal that hopefully could be used with an QAI module & a suitable trigger setting, and the D-type that hopefully could be used with a digital input on any of many modules ...

either way, it would be positioned as a beam-breaker - ie: looking across the direction of passage ...

hopefully, because the inputs & outputs are not quite ideal - ie: one or two extra components might be required to power it off IDRAnet and make it compatible with module interfaces

any thoughts, might it work ??

[westernm]

we've looked for a beam breaker sensor - sounds easy, but all we've found have been expensive and/or far from compact / simple to install ...

this seems to offer a slightly different approach that avoids such issues - it comes in two versions :

http://www.oomlout.co.uk/infra-red-distance-sensor-w-cable-p-229.html

http://www.coolcomponents.co.uk/catalog/resources/GP2D12IRSENSOR/GP2Y0A21YK.pdf

the A-type gives a signal that hopefully could be used with an QAI module & a suitable trigger setting, and the D-type that hopefully could be used with a digital input on any of many modules ...

either way, it would be positioned as a beam-breaker - ie: looking across the direction of passage ...

hopefully, because the inputs & outputs are not quite ideal - ie: one or two extra components might be required to power it off IDRAnet and make it compatible with module interfaces

any thoughts, might it work ??

I have been testing one of these on my network recently. I have it connected into a QAI. The response of the unit is quite good up to about 50cm which is perfect for what I need them for i.e doorways with no doors and stairs etc.
Also they can be set just hight enough in the door frame that the cats do not trigger them
With a little tweaking it may be possible to use them to detect direction of motion by inserting them into the frame at an angle and reading + or - deltas in the resulting input. (Still to be perfected though)

Mark

[chris_j_hunter]

that's interesting ... how did you wire it in to IDRAnet - simple resistance voltage dividers, perhaps, on both input & output, or ... and, if so, what values did you use ???

another & lower-cost approach, we've been thinking-about, might use this :

http://www.oomlout.co.uk/tilt-switch-p-243.html

mounting it so that, as people pass-by or open a door, it waves in the draught ...

more fragile & likely less-reliable, maybe ... !