Re: Sensors for doors & windows & ...

["Frank Mc Alinden" <frankmc@xxxxxxxxxxxxxxxx>]

Hi Chris

We use something similar to that with Gerry,s  RGBLED Sequencer.....
The problem is that solution will only let you know which way the door is
moving....you would still need at least one reed switch to say the door is
fully opened or closed as a reference......

Heres the one i use on my Sequencer
http://tinyurl.com/23ztz3

If  you wanted to know how far the door is opened maybe it would be better
to use an lvdt.....It would have to be recessed into the door frame somehow
....

HTH
Frank









----- Original Message -----
From: "Chris Hunter" <cjhunter@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Monday, October 29, 2007 7:08 AM
Subject: Re: [ukha_d] Sensors for doors & windows & ...


> 'wonder if something like this would be better than a potentiometer -
>
> http://www.usdigital.com/products/s4/
>
> with the string-approach, that is ...
>
> Chris
>
>
> On 28 Oct 2007, at 12:02, Chris Hunter wrote:
>
>> going a bit further ... maybe a string run between a point on the
>> door & spring-unit in the frame (or the other way around), to
keep
>> the string in-tension, would work, the string being wound-around a
>> potentiometer at some point between the two ends ... with an
>> additional pulley, the spring & the potentiometer could be
hidden in
>> the frame, or the door ...
>>
>> a linear slider potentiometer might be an alternative ...
>>
>> not sure about duty-cycle ...
>>
>> hmm, could be worth an experiment ...
>>
>> Chris
>>
>>
>> On 28 Oct 2007, at 11:41, Paul Gordon wrote:
>>
>>> I'd already thought of the very same idea, however, I'd rather
>>> thought
>>> the hidden variety would be preferable.. You may have seen the
hidden
>>> type, - it usually consists of a spring box which gets mounted
in the
>>> door frame on the hinge side, and a tensioned chain issues
forth &
>>> attaches to the hinge-side of the door.
>>>
>>> When the door is closed, no part of the mechanism is visible,
- much
>>> better for a domestic environment, where I can't really
imagine many
>>> SWMBO's being too happy with the rather industrial type shown
in the
>>> picture...
>>>
>>> Again, I would imagine it shouldn't be beyond the wit of man
to
>>> enhance
>>> this design to sense how much of the chain is fed out, which
>>> equates to
>>> how open the door is...
>>>
>>> Paul G.
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On
>>> Behalf
>>> Of Rob Iles
>>> Sent: 27 October 2007 20:55
>>> To: UKHA Group
>>> Subject: Re: [ukha_d] Sensors for doors & windows &
...
>>>
>>> How about - - for doors, and non-sash (sliding) windows ---
how
>>> about a
>>> pivoted arm and a potentiometer?
>>>
>>> I'm thinking of something similar to the
"soft-close" mechanisms you
>>> often
>>> find on doors in commercial premises - which consists of a box
>>> screwed
>>> to
>>> the door (hing side) - and two arms, hinged in the middle. the
>>> mechanism
>>> (spring?) inside the box cause the door to close when you let
go.
>>> (hopefully, by now, you all know what I'm talking about!) :)
>>>
>>> a picture may help - - http://tinyurl.com/yok7h4
>>>
>>>
>>> well, if you replace the spring/tension mechanism with a
>>> potentiometer -
>>> you'd get an analogue reading of door position. feed into an
A-D
>>> Converter,
>>> and with a little calibration, you could measure the exact
angle /
>>> amount by
>>> which the door is open.
>>>
>>> The commercial products are quite bulky, and might not fit
into your
>>> home
>>> decor (decreased SOAF) - - but they're the size they are as
they
>>> need to
>>> apply considerable torque to close the door (due to the
location of
>>> the
>>> mountings).
>>>
>>> You could probably build something significantly smaller, as
the two
>>> arms
>>> only need to turn a potentiometer - mount it in a discreet
box, and
>>> away
>>> you
>>> go :)
>>>
>>> If you think this is a fantastic idea, then I hereby claim -
in
>>> public -
>>> all
>>> IP rights/copyright/patent pending ;) .....and may (seriously)
>>> consider
>>> having some made!
>>>
>>> Thoughts?
>>>
>>> Rob
>>>
>>>
>>> On 10/27/07, Chris Hunter <cjhunter@xxxxxxx> wrote:
>>>>
>>>>   Gerry's boards ... presumably as in :
>>>>
>>>> http://www.rgbled.org/maxbotix/index.html
>>>>
>>>> up to twelve sensors per board sounds pretty useful !
>>>>
>>>> our PC has four RS232 sockets, one maybe two being spare
... so
>>>> could
>>>> be good for us, too (assuming I can link to Cortex) ... !
>>>>
>>>> Chris
>>>>
>>>>
>>>> On 27 Oct 2007, at 12:23, Kevin Hawkins wrote:
>>>>
>>>>> I'm intending using some of the Maxbotix ultrasonic
sensors
>>>>> pointing
>>>>> slightly diagonally across the doorways. These then
provide a
>>>>> direction
>>>>> indication for a person moving into or out of a room
(short to
>>>>> long or
>>>>> long to short reading) and based on distance you can
elimate
>>>>> outside
>>>>> false trips. I use Gerrys boards, only played so far
but seems
>>>>> viable,
>>>>> fortunately I have deep doorways in walls often 3 foot
thick. . A
>>>>> top
>>>>> mount sensor might even identify people based on
height- or the dog
>>> .
>>>>>
>>>>> I also have some Pulsor -strain sensors arriving any
day now -
>>>>> which
>>> I
>>>>> hope to use on the stairs and a couple of doorways.
>>>>>
>>>>> K
>>>>>
>>>>> Chris Hunter wrote:
>>>>>>
>>>>>>
>>>>>> 'thinking of sensors for doors & windows ...
and the
>>>>>> limitations of
>>>>>> the reed-switch (just open or closed & no
certainty on what it's
>>>>>> telling about the door, unless perhaps it's
attached to the
>>>>>> locking
>>>>>> mechanism in some way - which can't see how to do
as a retro-fit)
>>> ...
>>>>>> was trying to think how else ... strain-gauge ...
laser + mirror
>>> ...
>>>>>> all have just-as-bad limitations ... hmmm ...
>>>>>>
>>>>>> 'wonder if PIRs are all the same ... obviously
not, but in the
>>> sense
>>>>>> of being designed to pick-up just movement ....
are there some
>>>>>> that
>>>>>> are designed to pick-up position, say, or presence
not associated
>>>>>> with movement, or movement of hard but not soft
objects, or ... ?
>>>>>>
>>>>>> with MHVR, having doors or windows open might be
expected to
>>>>>> affect
>>>>>> the pressure in the house ... so, all closed =>
some
>>> pressurisation,
>>>>>> maybe, depending on the relative speeds of the
inlet & outlet
>>>>>> fans ... 'wonder if adding air-pressure-sensor(s)
to each room
>>> could
>>>>>> be useful ... picking-up both level &
fluctuations ... and so
>>>>>> doors
>>>>>> open, people moving-about, curtains wafting, pesky
flies,
>>>>>> whatever ...
>>>>>>
>>>>>> micro-phones are air-pressure sensors, of course
... wonder if a
>>>>>> broad or limited bandwidth one would be best ...
>>>>>>
>>>>>> hmmm ... would fuzzy logic be the thing, to make
it work ...
>>> looked-
>>>>>> up Wiki, but 'am really none the wiser, 'though it
did mention
>>>>>> pattern recognition as being an application for it
...
>>>>>>
>>>>>> rambling, sorry, but I feel there's a glimmer here
!
>>>>>>
>>>>>> or maybe I'm clutching at straws ...
>>>>>>
>>>>>> Chris
>>
>>
>>
>>
>>
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