Thanks for the helpful write up. Really needing some kind of physical controls for my nexus. New to arduino and steering controls but can't a simple inline aux volume toggle control for headphones and such be connected to the aux jack in the nexus and then be spliced into the arduino outputs? Or would I need the Metra kit? Im only running a nexus 7 to DAC to amp. No head unit. So the nexus itself is my audio output source/"head unit". Thinking that using a headphone control to control volume on android OS would be a simpler solution if possible. Also what does the source/2sec delay circuit do?
$51 on sonic electronix btw.
http://www.sonicelectronix.com/item_...ss-ASWC-1.html