At one time, there was a thread talking about ultrasonic
transducers, and interfacing with a PIC.  Looking thru my
saved mail, I don't see this.

So, sorry to ask again, but can a ultrasonic transducer be
driven directly from a PIC I/O pin ?  I believe there may
be some danger from the transducer drawing spikes of current
from the PIC, and possibly damaging it.  Also, if a single
pin can't supply enough current, can multiple pins be used
to drive the transducer ?  I suppose that the mask to the
output port is registered in fast enough that all the outputs
should switch at about the same time.  Of course the other
drawback is the amplitude of the signal being transmitted.

By range to detect is around 12-14", and is not a moving target,
giving me the luxury of taking multiple readings and determing if
the object is in the field of view.

Harrison Cooper
hcooper@es.com