Hi, I'd like to know how to connect my arduino to my android phone through the audio jack, and receive some data just like this: http://media.midwayusa.com/productimages/880x660/alt1/626/626107.jpg .
How is the Android phone sending the data?
In my project the android phone only needs to receive data, but I beleive it is possible to send data too, if you look at this (http://www.weaponeer.net/forum/forum_posts.asp?TID=13034&PN=4) it is a control that is sendind data shorting the 2 "audio" chanels