1 ## 2.4\. Watch Requirements 2 3 An **Android Watch device** refers to an Android device implementation intended to 4 be worn on the body, perhaps on the wrist. 5 6 Android device implementations are classified as a Watch if they meet all the 7 following criteria: 8 9 * Have a screen with the physical diagonal length in the range from 1.1 to 2.5 10 inches. 11 * Have a mechanism provided to be worn on the body. 12 13 The additional requirements in the rest of this section are specific to Android 14 Watch device implementations. 15 16 ### 2.4.1\. Hardware 17 18 Watch device implementations: 19 20 * [[7.1](#7_1_display-and-graphics).1.1/W-0-1] MUST have a screen with the 21 physical diagonal size in the range from 1.1 to 2.5 inches. 22 23 * [[7.2](#7_2_input-devices).3/W-0-1] MUST have the Home function available 24 to the user, and the Back function except for when it is in `UI_MODE_TYPE_WATCH`. 25 26 * [[7.2](#7_2_input-devices).4/W-0-1] MUST support touchscreen input. 27 28 * [[7.3](#7_3_sensors).1/W-SR] Are STRONGLY RECOMMENDED to include a 3-axis 29 accelerometer. 30 31 * [[7.4](#7_4_data-connectivity).3/W-0-1] MUST support Bluetooth. 32 33 * [[7.6](#7_6_memory-and-storage).1/W-0-1] MUST have at least 1GB of 34 non-volatile storage available for application private data (a.k.a. "/data" partition) 35 * [[7.6](#7_6_memory-and-storage).1/W-0-2] MUST have at least 416MB memory 36 available to the kernel and userspace. 37 38 * [[7.8](#7_8_audio).1/W-0-1] MUST include a microphone. 39 40 * [[7.8](#7_8_audio).2/W] MAY but SHOULD NOT have audio output. 41 42 ### 2.4.2\. Multimedia 43 44 No additional requirements. 45 46 ### 2.4.3\. Software 47 48 Watch device implementations: 49 50 * [[3](#3_0_intro)/W-0-1] MUST declare the feature 51 `android.hardware.type.watch`. 52 * [[3](#3_0_intro)/W-0-2] MUST support uiMode = 53 [UI_MODE_TYPE_WATCH]( 54 http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH). 55 56 Watch device implementations: 57 58 * [[3.8](#3_8_user-interface-compatibility).4/W-SR] Are STRONGLY RECOMMENDED 59 to implement an assistant on the device to handle the [Assist action]( 60 http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST). 61 62 Watch device implementations that declare the `android.hardware.audio.output` 63 feature flag: 64 65 * [[3.10](#3_10_accessibility)/W-1-1] MUST support third-party accessibility 66 services. 67 * [[3.10](#3_10_accessibility)/W-SR] Are STRONGLY RECOMMENDED to preload 68 accessibility services on the device comparable with or exceeding functionality 69 of the Switch Access and TalkBack (for languages supported by the preloaded 70 Text-to-speech engine) accessibility services as provided in the 71 [talkback open source project]( https://github.com/google/talkback). 72 73 If Watch device implementations report the feature android.hardware.audio.output, 74 they: 75 76 * [[3.11](#3_11_text-to-speech)/W-SR] Are STRONGLY RECOMMENDED to include a 77 TTS engine supporting the languages available on the device. 78 79 * [[3.11](#3_11_text-to-speech)/W-0-1] MUST support installation of 80 third-party TTS engines. 81
