Remote shutter - Transistor madness (or some other sort) Answered
I'm trying to build remote shutter for my camera. Intervalometer to be exact. That doesn't really matter. I have this page http://www.robotroom.com/Macro-Photography-2.html describing how to make a simple remote shutter. The schema is simple - trivial. However, instead of 2 physical switches, I'd like to control it using audio signal from my smart phone. I'm a programmer and I can make an app that will output signal of any volume and frequency. I'd like to control these two switches using this signal. Those switches provide 4 positions, however only 3 are needed - nothing, focus, shutter.
Can anyone adjust that schema, add (probably) transistors or some other parts if needed to make this happen? Remote shutters for other cameras (Canon, Nikon, Pentax, ...) work in similar way, so similar schemas can be derived to serve whole range of digital SLRs.
Motivation: I don't want to buy costly and redundant intervalometer, I can create nice app for Android which can work together with just small DIY piece of analog circuit to create wonderful timelapse videos.