Dear PIC Specialists,

I construct a AUDIO Freqency (here: 100 - 1100 Hz) MEASUREMENT device
with a PIC16C84 as the brain.

But in the moment is my PIC a bit deaf. Has somebody IDEAS how I can
connect as easy as possible a tiny 64 Ohms Loudspeaker (that must be beacause
of the big other Part of my Circuit) with the PIC, using only low Power  single
+5 Volts Supply.

I try it in the moment with a Automatic Gain Controlled OpAmp and a Schmitt
Trigger (build of two CA3140 and one VN10LM). But because of my little
knowledge in Non Symmetrical Supplied OpAmps, it does'nt work.

If You've any useful Links, hints, Your own Experiences with this, or
-much better- working Circuits, reply to PICList and say, if I can contact You
directly, please. Because I'am interested in GIF, WMF,  ... Pictures, or
Quickroute Schematics /Circuit Descriptions as Examples of a suitable Circuit.

I 'am grateful for every Help,
              Bernd