I want to use the short audio output from my iPad to generate a brief 5V pu lse for an Arduino circuit. I am using an existing pre-amp to take the roug hly 200mv pk-pk ac to about 8V pk-pk. I thought I?d follow that wit h a simple 4-diode bridge rectifier. The pre-amp and the Arduino circuit ha ve a common ground rail. So is the correct method to take each of the pre-a mp outputs to the bridge via a capacitor? Using 0.1uF, this appears to work OK (with a 4.7V zener to keep the pulse under 5V). But it does look a bit strange, so I?m wondering if there?s a neater way please?