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I am a completely beginner. Could anyone give some suggestion to my enquiry??

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ponyta

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Dear all,
i am a completely beginner about sensor and connecting sensor to a computer. Please don't mind that may be i am asking some stupid questions.

I am doing a project which need sensor to detect whether a person is standing inside a specific area.

If the person is standing inside that area, a device which have pwoer supply will turn on and also a C++/flash program inside a computer will run.

If the person then stand outside the area, we device will turn off and the program inside a computer will stop.

Could anyone tell me that which sensor i should use and how to connect it to the device to control on/off and connect into a computer and let the program to get the variable?

Thanks very much
 
Can you describe the "specific area"? What defines the accuracy of "inside" the area and "outside".
Detail...details...details! It will help. :)

Ken
 
Can you describe the "specific area"? What defines the accuracy of "inside" the area and "outside".
Detail...details...details! It will help. :)

Ken

there is a telehphone putting on a shelf at a wall.
if the person stand in front of and close to the telephone(less than 30cm), the lights will turn on and the computer will start running the program.
if the person go away or far away from the telephone(more than 30cm), the lights will turn off and the program will stop

thank you very much.
 
This might be accomplished with either an IR beam-break or a shielded PIR circuit. Can you post a drawing of the exact layout of the area? Both floor plan and layout of the wall with the shelf.

Ken
 
This might be accomplished with either an IR beam-break or a shielded PIR circuit. Can you post a drawing of the exact layout of the area? Both floor plan and layout of the wall with the shelf.

Ken

I am afraid i don't have the floor plan now. Sorry.

Is the IR beam-break and a shielded PIR circuit work like the sensor of the Automatic-Door?
I have no idea about how the sensor work, but i think the sensor of the Automatic-Door can fit my requirement.

Moreover, how can i connect those sensor to a electronic device and computer?
 
Some commercial door sensors are infrared (like PIR sensors) that sense the body heat, and some are microwave (like RADAR) that sense a reflected wave. Not cheap.
There would probably be a switch closure that could be detected by a serial or parallel port on the computer.

Can you do the programming?

Ken
 
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Some commercial door sensors are infrared (like PIR sensors) that sense the body heat, and some are microwave (like RADAR) that sense a reflected wave. Not cheap.
There would probably be a switch closure that could be detected by a serial or parallel port on the computer.

Can you do the programming?

Ken

Is the PIR sensors cheap?
i have programming knowledge about C++ and actionscript3.0. But i have no idea how to get the variable from the sensor.
 
I have no idea where you are, where you can purchase parts. (Please add your location to your forum profile.)
PIR sensor: PIR Sensor Module - RadioShack.com
Data Sheet: PIR Sensor Module This shows a single transistor circuit that could be used to switch a serial or parallel port on the computer. Because of the wide sensor viewing angle, you would need to shield to limit it to a small area.

Ken
 
I have no idea where you are, where you can purchase parts. (Please add your location to your forum profile.)
PIR sensor: PIR Sensor Module - RadioShack.com
Data Sheet: PIR Sensor Module This shows a single transistor circuit that could be used to switch a serial or parallel port on the computer. Because of the wide sensor viewing angle, you would need to shield to limit it to a small area.

Ken

I am living in Hong Kong, i added my location to my profile now. Sorry.
may i know how much does the PIR sensor and the data sheet cost in US generally?
 
The PIR price was on the link page...$9.99US. The data sheet is free to download.
Google: PIR Sensor Module
You will probable find vendors in you part of the world.

Ken
 
i found the vendors through this page: **broken link removed**

After i bought this PIR Sensor Module, how can i connect to the computer and get the variable and use in C++ program and control the on/off of a device?
 
I'm not sure which one you purchased. There doesn't appear to be any datasheets for them. Perhaps one will come with it. The one I'm familiar with has (+5V)(Com)(Out) pins.
I'm not a programmer so you will have to research that your self. Which ports do you plan on using? Looks like there is info here:
Google: C++ parallel port
Google: C++ serial port

Ken
 
One more question. Sorry.

If i have some light bulbs connecting to AC power supply.
How can i connect the sensor so that it can swtich on the light bulbs when the person is in front of the sensor and switch off the light bulbs when the person away??
 
Switching can be done with electromechanical relays or solid state relays (SSR). What is the voltage and wattage of bulbs? How many? You will need a low voltage power supply for the PIR and switching circuit, but this can be a small 5.0V cell phone charger. I pick used ones up in second-hand stores for $0.39US

Ken
 
Switching can be done with electromechanical relays or solid state relays (SSR). What is the voltage and wattage of bulbs? How many? You will need a low voltage power supply for the PIR and switching circuit, but this can be a small 5.0V cell phone charger. I pick used ones up in second-hand stores for $0.39US

Ken

Actually, it is a light with 220V and 300W.
 
The attached has two options that should work. The upper one uses an electromechanical relay...cheaper. The lower one uses an SSR...quiter. Ignore my PIR's pin numbers. Use the +/-/Out designated on the one you get. What is the part # of the PIR you ordered?

Ken
 

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