| Robert Ly | 35f2fda | 2013-01-29 16:27:05 -0800 | [diff] [blame] | 1 | page.title=Android Open Accessory Protocol |
| 2 | @jd:body |
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| 19 | |
| 20 | <p> Android Open Accessory support allows external USB hardware (an Android USB accessory) to interact |
| 21 | with an Android-powered device in a special accessory mode. When an Android-powered powered device |
| 22 | is in accessory mode, the connected accessory acts as the USB host (powers the bus and enumerates |
| 23 | devices) and the Android-powered device acts in the USB accessory role. Android USB accessories are |
| 24 | specifically designed to attach to Android-powered devices and adhere to the Android Open Accessory |
| 25 | Protocol, that allows them to detect Android-powered devices that support |
| 26 | accessory mode. Accessories must also provide 500mA at 5V for charging power. Many previously |
| 27 | released Android-powered devices are only capable of acting as a USB device and cannot initiate |
| 28 | connections with external USB devices. Android Open Accessory support overcomes this limitation |
| 29 | and allows you to build accessories that can interact with an assortment of Android-powered |
| 30 | devices by allowing the accessory to initiate the connection.</p> |
| 31 | |
| 32 | |
| 33 | <p><strong>Note:</strong> Accessory mode is ultimately dependent on the device's hardware and not all devices |
| 34 | support accessory mode. Devices that support accessory mode can be filtered using a <code><uses-feature></code> |
| 35 | element in your corresponding application's Android manifest. For more information, see the |
| 36 | <a href="http://developer.android.com/guide/topics/connectivity/usb/accessory.html#manifest">USB Accessory</a> |
| 37 | developer guide.</p> |
| 38 | |
| 39 | |
| 40 | <p>Android Open Accessory support is included in Android 3.1 (API Level 12) and higher, and supported |
| 41 | through an <a href="https://developers.google.com/android/add-ons/google-apis/">Add-On Library</a> in Android |
| 42 | 2.3.4 (API Level 10) and higher.</p> |
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