[sdiy] Proximity detector

[Paul Perry]

At 05:12 PM 17/03/04 +0100, Fredrik Carlqvist wrote:
 Preferrably, they would output a voltage
>proportional to the distance of the body.
>
That is a bit of an ask (the distance part) but,
depending on the range you want, there is an
ultrasonic ranging module made by Polaroid (and 
used in amateur robotics, cameras etc).

A PIR security senser (burglar alarm sensor, the type
in the corner of the room that flashes red when it 
detects someone moving around) can be hacked, but
it isn't going to give a distance measurement.

paul perry Melbourne Australia