Keep in mind the Arduino is directly coupled to the output of your device.
The Arduino will not like a negative input on that signal input so you should either cut the wave-form in half... or put a decoupling capacitor in-between, reduce the output to maybe about 2V p-p and add a DC offset so that the Arduino ADC reads roughly 50% when there is no output.
Thanks for bringing this up. This is pretty important to know.
Could you explain a bit further what you mean by the options of either cutting the wave in half, or using a decoupling cap and DC offset? These are new terms to me.
As far as I can tell (doing quick research), you mean to read in only the positive peaks of the waves for cutting the wave in half?
And for the DC offset, you mean to keep the wave normal but offset it above the 0V threshold so that I can read in the whole wave (basically shifting the whole wave above the 0V threshold so that it's all positive)?