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.
Např. Accessory Development Kit od Googlu je open-source a založený na Arduino, na rozdíl od podobné technologie od Applu, která je uzavřená, pod závazkem mlčenlivosti -- upište váš život Applu. Tady to je.