Help me find a wireless sensor/switch! Thanks!

Check out the ultrasonic sensor kits at your local electronics shop - one of those will do the trick - it will provide switch closure output. You need a McPerson to tell you how to connect it to the Mac - Cheers Pete

Thanks Pete! I'll do that.

Just put the mouse button under one of the chair legs so that when a person sits in the chair, the button gets pushed. I have never dissected a Mac Mouse but it should not be too difficult to get into it and parallel the switch contacts. A common hardware store motion light infrared sensor or similar could be used to do the same thing if one were wired to pull in a relay across the mouse switch.

That is just two rabbit brained ideas, I don't think they are quite large enough to be classified as hare brained.

GA

Hello bwire,

I hope you are fine...................

Ga for me, Sir, you are very kind, I thank you sincerely from the heart of my bottom...........

Uuuummmm.........I think I got that wrong?..........But A than you anyway Mr wire!

Take care.................

Hello,

I forgot to ask, What time does the CR4 Stories come out each day in the States?

It seems to vary here in the UK and Europe. Anywhere between 00:200/00:500.

Take care

On the west coast, typically 2100L to 2200L. We are 7 or 8 hours minus from Zulu time depending on daylight savings time.

Bill

Hello Sciesis2:

I assume you mean by 'zulu time GMT'? So that would make the time I get them about correct. IE. If you get them at 21:00, I get them at 04:00?

I am a radio Ham Listener, and have a Great Circle Map but someone tidied it away and so I have to work out rough what time zone they belong in, to get an idea if they may be or should be likely to be in bed soon?

The reason I ask and it is odd sometimes, when I get them through on my computer there is often a whole lot of questions already answered, with some substantial replies. If we get them at the same time there should be no reply (in theory)?

Many thanks for the reply post my friend. I can now climb down from the roof I was going to shout at CR4 from!!!!!!!

To confess... For me, CR4 is much like a pot of tea. It is much better if it steeps for a while. I won't open tonites CR4 until tomorrow some time. I learn alot more that way.

In the radio world, we use 24 hour time and suffix it with "L" for local time and "Z" for zulu time (or GMT). In international communications (say I was talking to someone in Russia), things are much easier if everyone uses zulu.

Sincerely

Bill NW7L

Cheapest and simplest sensor: a suitable microswitch between 2 flat pieces of plastic.

Simplest wireless yes/no transmission: Bluetooth (if macs use it).

there are so many ways to interpret the intended end use of the device other than attached to a chair in a movie theater. can you pass a bit more info about the rest of the picture,e.g. what will the surroundings or other mechainical electronic influences on the end use be?

will a weight body mass factor be involved? does height and width of the users intended become a factor(s)?

'da ber

Thanks for all your responses! I'll try to explain a bit more: This is a video installation, that is like a movie theater like setting, except for that I will be using regular fold in chairs. I will be showing it several places, such as galleries, festivals etc, which means all the rooms will be different, amount of light, temperature, what other interactive art installations will be close by, all this will change. And the idea is, that whatever sensor/switch I will use as a trigger, will be portable, so I don't have to permanently attach them to the chairs (there's 9 seats all together), but instead I can rent any chairs locally and just attach my sensors to it. I will be running the actual program from a laptop or desktop computer, which will be hidden behind some sort of wall or curtain, so it's not visible, depending on the space. So the system should be not too sensitive, so that it could adapt to different situations. Also, the important thing is, that when people sit on any of the chairs, up to 9 people will be doing this simultaneously, and so the switches should not interfere with each other. And when a person sits on a chair, a movie should start playing instantly, and it shouldn't really matter what the distance from the back of the chair or the weight of the person is etc, it should be pretty clear: person sits on chair=the movie plays. Does this clarify a bit more? Thanks again for all your advice!

Hello taankk thank you for feedback,

DIY project and science project 'electric eye'

Or

Sensors that detect heart beats are used in high security systems

Hello taankk:

Just to say how can you be sure any other 'act' will not interfere with your signals?

I know it is not part of your plan but, it may pay to keep a wired setup, that could be hidden under a mat just in case, phones and or radios start to be a nuisance?

Good luck!

Sir

You might try your local home building center. I just got back from mine & they had 2 units that consisted of a wireless switch & wireless relay kit. The cost was $8.00 to $11.00 US.

The first unit used a push button switch the second unit had a rocker switch & the relay parts were rated at 250/300 watts.

The range given was "up to 35 feet". I have been using a device of this type to turn on & off a floor lamp at a distance of 10 feet for 2 years with perfect results.

The switches on these devices are purely wireless with a internal battery for power.

The control relay is plugged into the mains power & the device to be controlled is then plugged into it.

One possible drawback with most of these type units is that they work on the same frequency or code.

Regards

Doug

Thanks Doug! That sounds good, except that I want something other than a button you have to physically touch to make it turn on/off, to make it as seamless as possible for the user -with any kind of push type button you have to build some kind of a plate that covers it -I wouldn't want people sitting on the theater feeling a button on their back or their bottom! That's why I'm looking into something like infra red, distance, movement etc kind of a sensor rather than a switch, and need help because I'm not familiar with this kind of devices at all -I used a push button before but it made the physical user interface too clumsy. P.S. It's "Miss" rather than "Sir" : )

Hello 'Miss' taankk:.......

Have you had a chance to view any of the sites I sent?

It may complicate things slightly with there being, and forgive me here as I forgot how many chairs, I think it was 7 or nine? The reason for this is the number of transceiver frequencies. Most simple devices which may be suitable use maybe 2 or 3 frequencies. I suppose, as long as you knew all chairs would have a person, you would need perhaps a couple of switches.

I am thinking while I type here and, I can't usually do two things at once!

Have you had an definite ideas, other than some sort of 'distance switch'?

Is it that you do not want the show to start 'automatically' until the last seat is sat on? If this is correct, it may not matter about the frequencies, and whether the same two or three frequencies are sent and interfere with each other.

If you are using fold up chairs, you could perhaps use a piece of material to 'decorate' each chair back or seat, where in fact it will hold the sensor inside?

I am wondering if you could have a computer program running that counts '1' each time a chair is occupied, and when the last chair is occupied the program on the computer will start the show. Does that go with what you have in mind?

Can you tell me how much you can pay for these sensors? Because you must have some kind of budget? And I am going to check these sensors again to try and get some costs.

Please tell me if you have found an idea or type which you may be using.

Good luck...............

Hello taankk:

I may have had a brain-wave (or not), it depends if you like the idea.

How about each chair having a number and, say there is 9 chairs. As long as you can be sure the final (ninth) chair is occupied you could pass out numbers or ask them via a printed note to start and sit in chair 1 up to nine and, as the ninth one is filled, the show starts? The advantage is you would need only one sensor.

Thoughts please?

Thanks babybear! The installation works as follows: There are 9 chairs in the room. Each chair has a sensor/switch. When someone sits down on a chair, a movie assigned to that trigger plays on the screen. If another person sits on another chair, another movie will start to play simultaneously. There are as many movies on the screen, as transparent layers, as there are people sitting in the audience. Right now this is happening via hardwired push buttons, that are connected to a keyboard, each button is wired via electric cable to a number key on the keyboard (1-9). So for example, button on the chair no.1 is connected to the key "1" on the keyboard, which tells the computer program to start playing movie clip no.1. The installation keeps going on, it's not like a traditional movie that has a start time and ends when it's played through, but keeps looping. Hope this gives you more of an idea!

Hello taankk:

I ask you to forgive me if your question has been answered and you have ordered the pressure pads or whatever. I have not been getting any updates by email for over two days and you may have ordered the pads by now. I just wondered if the tiny, paper thin pads on my post 22 are the kind of thing you want?

And, if they are you could sellotape them to the chairs backs and cover the backs with a colourful scarf to make it look like decoration?

But you will also need a gizmos on the chair to plug the pad into and send you a signal? Have you checked for those? I can check but am not certain of if you want to get them from the US or UK? Does it matter, as they are sent by post anyway?

Good luck...............

Hi babybear, Thanks so much for all your great ideas, and this goes for everyone else who posted too! I am concidering from many options now, and I think that the thin pads you mentioned are on the top of the list now. I found online also that they actually make these ready made seat pad switches, that are mainly used for people with disabilities, but those are of course a bit expensive because they are special medical equipment. I also found this link on how to build your own mat switch: http://www.supersoda.com/detail.php?id=00000000036 and also ready made ones: http://www.t-sensor.co.jp/eng/mat/index.html The biggest problem remains how to make the switches wireless. If I only had one button it would be easier, but since I have 9 triggering simultaneously, I haven't found a way to tell the computer which button is getting trriggered, which is crucial for the installation to work. I may have to just give the wirelessness up. Sigh! It just makes the exhibit look clumsy and untidy, last time I taped all the cords on the floor with duct tape, but it just looks undesirable in an art gallery environment! Any ideas on concealing the wires? Thanks again everyone, taankk

I think I think you're giving up too soon.

Check out the selection of wireless garage door openers and you may discover a cure

A quick search found this system which has a wireless receiver & remote battery powered wireless switches. You would have to butcher re-engineer the switches to connect your pressure pad but it could work. There must be other similar systems out there which might be more suitable. Don't give up too easily.

Something like this might just do the trick! Thanks! I'll look into it further.

Hello taankk:

you mean a sender and receiver?

On the how to get the computer to do it. And before I start I admit to not being an expert in Excel. But it may hold a cure for your problem.

You can program 9 squares in Excel one for each chair. As the signal in sent from the chair to your computer the Formulae used will tell the program to go onto the next, and so on along the line. You should find the formulae in help? There is a help thing in excel. Or can you write macros?

Have you worked in excel before?

Just trying to help. There is a way because lots of other things work the same as you want your to work.

I already have the programming in place. The original was made in Apple's Xcode, and the current version with Apple's Quartz Composer. The program receives the commands through the keyboard's number keys, so the thing to solve will be how the wireless commands will be received by the program. I'll ask the programmer if he knows how to do this. I think as long as I have the 9 pads as triggers, a wireless converter for each and receiver that can distinguish between 9 wireless signals, I'll be fine, we can probably figure out the computer programming for that. So i think we're getting very close here!

I will have to PM you as I have just spoken to the technitials about the sensors and I have a ref # that you need to use if you want to continue to chat with them. Is that OK?

The sensor itself has two tabs which you can solder to any connection

Hello taankk:

http://www.google.co.uk/search?sourceid=navclient&ie=UTF-8&rlz=1T4GGLJ_enGB294GB294&q=Air+wave+switch

This is the google search site which lists lots of places for this Air switch.

I came across this when I was looking for something else. Its called 'Air Wave Switch'. I was thinking if it is affordable you could stick one to the back of each chair with gaffer tape. It will not be obvious and can't be ripped off.

I have to look at it in more detail but, thought I would tell you as my dinner was cooking.

Can you let me know if you are still continuing with this project please?

Take care and happy holiday.............

Hello taankk:,

are you able to click on the item number you would ideally like to use?

Because I am talking to the sensor people now but, it may be better if you could chat to them?

I am not sure they can help yet. But there is a chat line on the site.

How about visiting your nearest car breaker, most modern cars have a pressure switch in the seat to detect when someone sits in it exactly as you require. They are used either to trigger the seatbelt warning or to enable the passenger airbag. You could even just use the whole car seat in your installation.

Hmmm, not a bad idea. The car seat won't work, because it needs to be easily portable, so I'm really just looking for a tiny little sensor, but the pressure switch could work if they are available separately. I'll ask around for that. Thanks!

Hello taankk:

I found this thin film SENSOR PIEZO FILM VIBRA TABS, just £1.88

Digi-Key Part Number	Manufacturer Part Number	Description	Series	Manufacturer	Features	Capacitance	Package / Case	Sensitivity	Interface	Temperature Range	Contact Capacity	Mounting Type	Quantity Available	Minimum Quantity	Unit Price GBP
MSP1006-ND	0-1002794-0	SENSOR PIEZO FILM VIBRA TABS	*	Measurement Specialties Inc/Schaevitz	0.005"(125µm) polyester layer laminated to a 28µm piezo film element	0.500nF	PC Mount with Solder Tabs	50mV/g	PC Board Mount	-	-	-	8,675	1	1.58000
MSP1007-ND	0-1005447-1	SENSOR PIEZO FILM VIBRA MASS	*	Measurement Specialties Inc/Schaevitz	0.005"(125µm) polyester layer laminated to a 28µm piezo film element	0.420nF	PC Mount with Mass and Solder Tabs	50mV/g	PC Board Mount	-	-	-	5,473	1	1.88000

Any good?

Hello taankk,

I sent the last post to soon. I found a cheaper sensor and a picture:

When requested quantity exceeds displayed pricing table quantities, a lesser unit price may appear on your order.
You may submit a request for quotation on quantities which are greater than those displayed in the pricing table.

Any good?

Put a pad with the pressure switch inside on each of the 9 seats. After the show, collect the pads and be off to the next location.

Bill

Hello taankk:

hope you are fine.........................

Just wondered if you have gotten any further with the senders etc?

Good luck...............

Hello taankk,

found this site which has several types of switches which may suit your plans?

The One-way light barrier BIRCHER REGLOMAT
EasyBeam™

is the obvious choice here but theres also a touch sensitiv may at the bottom of the page.

http://www.directindustry.com/prod/bircher-reglomat/pressure-wave-switch-5583-23972.html

Inductive signal transmitter BIRCHER REGLOMAT INTRA50

Pressure sensitive safety edge BIRCHER REGLOMAT

Motion and presence detector BIRCHER REGLOMAT Jupiter

Passive infrared motion detector BIRCHER REGLOMAT PIR 20 / PIR 30

Active infrared motion and presence detector BIRCHER REGLOMAT EasyScan

Active infrared switch BIRCHER REGLOMAT CleanScan

Active infrared presence detector BIRCHER REGLOMAT TopScan/RevoScan

Active infrared presence detector BIRCHER REGLOMAT SpotScan™

Active infrared presence detector BIRCHER REGLOMAT AIR 20

One-way light barrier BIRCHER REGLOMAT EasyBeam™

One-way light barrier BIRCHER REGLOMAT ClearBeam™

Time delay relay BIRCHER REGLOMAT

Pressure sensitive safety mat BIRCHER REGLOMAT

| All the industrial Manufacturers | Supplier, Dealer and Distributor listing | Quotes, price list | Comparative test
| Technical characteristics and specifications | Documentation and PDF catalogue | New and used sales directory |

Take care and have a great holiday..................

Thanks babybear, these all look great. I think I do have now a wide selection of different switches I could use -my remaining problem is how I could make it wireless in a way that fits the programming -I'm sure there are lots of senders and receivers available, but it remains to be seen how it can be programmed so that the computer is able to receive the commands in a way that enables it to recognize which seat the signal is coming from. I think this is more of a programming/computer hardware/ software issue, so I'm trying to solve that with the programmer and searching other web sites -I don't think this is the right forum for that? Thanks for all your help, and everyone else too! It has been very interesting looking into all these different kinds of options out there, and I've learned a lot. I'll let you know how it all worked out in the end and what type of switch I ended up using. taankk

Hello taankk,

I think this Engineering section and the software/computer section compliment each other really. There is a cross-over, you know? So being on both would perhaps be ideal.

I have asked a friend about this and hopefully he will be getting back to me very soon. If you chose the very small pressure sensors it would be ideal and cheap to be able to solder them to a very small wireless device. But finding where to connect to tiny radio and getting the signal to the computer is the problem, as you say.

I am invalid and solving this would greatly improve my situation, so if you do sort it can you let me know?

You said you had software? Do you know how to use Excel? I am still trying to sort it out, but I know you can use Excel to switch from receiving one signal, acknowledging it, then ignoring it after the video starts, and going on with the next one.

Take care, and have a happy holiday..............