Post by thread:Audio Frequency Input ?

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

"Bernd.S" <spam_OUTeen6bsTakeThisOuTELECTENG.LEEDS.AC.UK> wrote: > 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 If you're using the speaker as a microphone, why not consider using an electret mic instead - electret microphones have a built-in amplifier and will have a higher output level than a speaker used as a mic. They're also small and cheap (they can be ratted from old cassette recorders too). Clyde -- Clyde Smith-Stubbs | HI-TECH Software, | Voice: +61 7 3354 2411 .....clydeKILLspam@spam@hitech.com.au | P.O. Box 103, Alderley, | Fax: +61 7 3354 2422 http://www.hitech.com.au | QLD, 4051, AUSTRALIA. | --------------------------------------------------------------------------- For info on the World's best C cross compilers for embedded systems, point your WWW browser at http://www.hitech.com.au, or email infoKILLspamhitech.com.au