make a sound trigger for my camera

[tejeshwar]

hiiii,wana make a sound tigger using my pic 16f73 kit,getting confuse where to attach a mic?
port a ie adc convrtr ,it wil use 2 port pins or single?or give me some advice or coding ,i know to use 1 adc port,,helpppp????????????????????

 

[alec_t]

IMO you will need a pre-amplifier between the mic and the PIC. The pre-amp would provide selectable gain/sensitivity and possibly filtering to prevent unwanted sounds from causing false triggers, depending on your intended use. A port pin with a Schmitt input function would suffice to handle the pre-amp output without having to bother with ADC.

 

[MikeMl]

I built one for a pro photographer friend of mine. He used it to get pictures of the space shuttle lift-off in Florida, using a Nikon with a motor drive and a 36 exposure roll of Kodak EktaChrome... It was mounted near the Gantry where no humans could be, so it had to be triggered by the sound of the engines firing.... We also included a few seconds of delay before the first exposure to give the engines time to come up to full power for the actual liftoff...

No PIC, just a couple of transistors to amplify a microphone, a couple of diodes to rectify the audio, and a small relay to fire the motor drive. It also had a clock to wake it up at the earliest scheduled launch time, so that trucks and other human movement prior to launch didn't set it off. It had to be placed about 12 hours prior to the scheduled launch.

 

[alec_t]

so it had to be triggered by the sound of the engines firing...

I'm surprised the transistors were needed if it was that close to the engines . Nice project, though.