RFID OR GPS OR XYZ?

[Ravi Shankar Nair]

Dear all,

I need to write a Java Program:- Assume that there are two devices. Whenever
the devices move, I want one receiver to identify that they have moved and
send signals accordingly to my server program. What technology I should use?
And what I need to buy (any kits or tools or software etc) to implement
this? Please help, thanks

It would be great if I can program the reciever so that I can control to
what extent the client devices can move, say not beyond 1 meter etc. Can
anyone please help?

Regards,
Ravi

 

[Roedy Green]

It would be great if I can program the reciever so that I can control to
what extent the client devices can move, say not beyond 1 meter etc. Can
anyone please help?

your basic device you need is a accelerometer with a wireless
connection. GPS would not be useful at those small distances.

Another sort of device you could use in the thing Polaroid used in its
SX-70 cameras. They bounced a beam of sound, ultrasound, ? and
listened for the echo to get distance. You could use them pointed in
various direction to measure distance to the nearest wall.

If the thing in on wheels, you can measure rotation very easily with a
square wave detector mounted on the axle -- the sort the old
mechanical mice used.

You could mount an optical mouse on the bottom of the device and have
it scan the carpet as is goes rolling by. That would be the cheapest
way to fly. Years ago Logitech sent me a book on how to write mouse
drivers -- how these things work at the lowest level.

 

[Roedy Green]

You could mount an optical mouse on the bottom of the device and have
it scan the carpet as is goes rolling by. That would be the cheapest
way to fly. Years ago Logitech sent me a book on how to write mouse
drivers -- how these things work at the lowest level.

The ultimate cheapie solution would be a WIRELESS optical mouse.

 

[Luc The Perverse]

The ultimate cheapie solution would be a WIRELESS optical mouse.

LOL - if there terrain were VERY smooth (like a table) then that would
actually work quite well

 

[Roedy Green]

LOL - if there terrain were VERY smooth (like a table) then that would
actually work quite well

they might even work hovering slightly. My wired mouse will work
hovering perhaps 0.5 centimeters in the air.

 

[Ravi Shankar Nair]

Dear all,

Thanks for your help. Yes, as the boss Roedy Green had suggested, let me
start with optical mouse and will trpuble you )) if I encounter any
glitches..

Best regards,
Ravi