Question about Sensors?

[supremek81]

I have an idea but I am not very savy when it comes to electronics. I need some help. I have an idea that would involve a sensor that would be able to detect when it is being covered up, and then it would be able to send a signal to another device that would then detect this signal and sound an alarm. The signal would only need to be sent when the sensor and the device are 3 ft. apart. The sensor could be covered up by something as simple as a hand, but it would need to be able to send a signal when the device is 3 ft apart. If the sensor is not covered up and the device goes 3 ft or beyond it will not sound an alarm. I hope this clear. If anyone has a question I can try to explain better. What would I need to creat this. Thanks in advance for any help.

 

[Leftyretro]

I have an idea but I am not very savy when it comes to electronics. I need some help. I have an idea that would involve a sensor that would be able to detect when it is being covered up, and then it would be able to send a signal to another device that would then detect this signal and sound an alarm. The signal would only need to be sent when the sensor and the device are 3 ft. apart. The sensor could be covered up by something as simple as a hand, but it would need to be able to send a signal when the device is 3 ft apart. If the sensor is not covered up and the device goes 3 ft or beyond it will not sound an alarm. I hope this clear. If anyone has a question I can try to explain better. What would I need to creat this. Thanks in advance for any help.

Does the sensor have to be able to detected being covered in total darkness as well lighted conditions?

Lefty

 

[supremek81]

I never thought of darkness, but yes it would. Thanks

 

[Torben]

I never thought of darkness, but yes it would. Thanks

So a simple light detector won't work.

What kinds of materials must it be capable of detecting? Anything? Or mostly hardish things (a hand, a piece of paper, what?) Would you need it to be able to detect, say, a big ball of soft fluffy material?

How big can the sensor be?

If mostly hardish things would need to be detected, you might be able to use a simple ultrasonic rangefinder to detect when something is directly above the sensor. These will detect the hand, paper, wood, etc, but might have trouble with textiles or foams.

Someone with more experience than I would have to advise you on what might be available if the thing has to be able to detect any object.


Torben

 

[supremek81]

It would only need to detect hardish things. The sensor would need to be small, like the size of a credit card or smaller. Also it would need to be able to send a signal to a device that would then sound a alarm. The device would need to be something you could carry around. Maybe something that would be able to be attached to your car keys or something. But the device would not need to sound until it separates at least 3ft. from the sensor and only if the sensor is covered up.

 

[Torben]

It would only need to detect hardish things. The sensor would need to be small, like the size of a credit card or smaller. Also it would need to be able to send a signal to a device that would then sound a alarm. The device would need to be something you could carry around. Maybe something that would be able to be attached to your car keys or something. But the device would not need to sound until it separates at least 3ft. from the sensor and only if the sensor is covered up.

Does it have to work no matter which orientation the sensor device is in? i.e. are you expecting that it would have to work when upside down, set on end, on its side, etc?

How thick can it be? The size of a credit card--do you also mean as thick as a credit card? I'm guessing that an inch thick would be too much.

What is the maximum distance this thing needs to work at? Need an upper bound (3 feet is the lower bound). Would it need to work up to 100 feet away? 500 feet? A mile?

How do you define "covered up"? Is it considered covered if it's put into a shoebox with a lid on it? How about a 1 meter cube box with a lid?

Perhaps if you explained what you're trying to do (what problem this device is intended to solve) it'd be easier to figure something out.



Torben

 

[supremek81]

The oreientation of the sensor would be set, meaning the sensor would be mounted into place so it would not move. It would need to work about 100 ft. away. What I mean by cover up is if something came across it that blocked it. Kinda like in the public bathrooms when you go to put you hands in the sink the water automatically comes up because the sensor detects that something is in front of it. It would need to work like that, but it would need to be able to send a signal once it is blocked or covered up. What is your e-mail or yim or aim and we can go more into detail. Thanks