[sdiy] [AH] Buffer +/-5V square wave to 5V for Arduino in?

[r- jeancarlo]

A diode and a resistor should do the trick.

> On Jan 3, 2015, at 10:39 AM, "Jack Jackson" <jackdamery at hotmail.co.uk> wrote:
> 
> Hi All, I'm working on a synth to MIDI project.
> 
> My VCO puts out a +/-5V square wave, I want to read its frequency using the Arduino
> digital in pin, but I'm aware it will probably blow it up if I feed it straight in.
> 
> How can I buffer it so it becomes a safe 0-5V square wave?
> 
> Cheers,
> Jack
>