So the Accessory Development Kit from Google is open-source and based on Arduino, as opposed to the one from Apple which is closed-source, NDA, sign your life to Apple. Here you are.
Tako je i "Accessory Development Kit" od Googla, otvoreni kod baziran na Arduinu, za razliku od onog koji koristi Apple, koji je zatvorenog tipa, tajan, povjerljiv, "prodaj dušu Apple-u".