At 11:32 AM 7/12/96 -0400, you wrote:
>I am working on a project that needs to find the distance to objects.
>Currently I am using using a PIC16C84 as my controller. I'm using 40kHz
>transmit and recieve transducers from polaroid.  Any suggestions to
improve >my design? I want a range of
>2-15 feet accurate within only a foot. Also,does anyone know of a way to
>narrow by field of detection. My current design detect objects off to
>the side.


This site has much on ultrasonic ranging using the pic16c84.
http://www.mindspring.com/~sholmes/robotics/ultrasw.htm

Glen Benson