Hello to everybody! I'm quite new to the arduino and programing world but I have in mind a cool project, and therefore I will need a little guidance. I whant to build some kind of robot (or whatever you can call it) that can feel the presence and the movement in the nearby are, let's say not bigger than a room. It must to be able to feel if the object is moving or if it's stationary, if it's far away or close, I'm not interested in exact position. The area is not big, and at this point the size is not a issue. I have been looking around and I found that you can set up a Bluetooth device to feel another Bluetooth, and in the same time the device can say haw far is the other one from him by measuring the intensity of the Bluetooth signal. My questions is if it's possible to build something like that with Arduino.
Thank you very much for your time!
You need at least a BT module that reports the intensity of the other BT device.
But I'm not sure if that helps. BT modules may adapt their transmission power, depending on the distance of the receiver (power save option).
I found thin online, http://www.openbeacon.org, the Beacon looks exactly as something that I ned, my question is, can an arduino Bt read the intensity of the Bt signal or you need more processing power?
Before you spend any money, if you have an android phone/tablet and a WIFI network, download the free WIFI Analyzer app. This can plot a "time graph" showing how the signal strength changes as you move your phone/tablet in relation to the WIFI access point. You may be surprised at how erratic the changes are.
The 2.4GHz bluetooth / WIFI band has a wavelength of about 12cm so diffraction effects mess up your ability to judge short distances. Just moving my phone around on my desk 5 meters from a WIFI access point causes the signal strength to vary between -55 and -70dBm.