USB-C-to-Analog Audio Adapter

From 43777eee371e6f873e7757bbaab25763b7ed1053 Mon Sep 17 00:00:00 2001 From: Android Partner Docs Date: Tue, 13 Feb 2018 12:14:30 -0800 Subject: Docs: Changes to source.android.com - 185568049 Typo in the usb adapter spec by Danielle Roberts - 185454531 Devsite localized content from translation request f937f9... by Android Partner Docs - 185454519 Devsite localized content from translation request 379736... by Android Partner Docs - 185454514 Devsite localized content from translation request 92bc2c... by Android Partner Docs - 185454118 Devsite localized content from translation request fc1572... by Android Partner Docs - 185454110 Devsite localized content from translation request 465ee3... by Android Partner Docs - 185454102 Devsite localized content from translation request ff994d... by Android Partner Docs - 185441660 Devsite localized content from translation request 2d6e3e... by Android Partner Docs - 185441584 Devsite localized content from translation request dcfc8e... by Android Partner Docs - 185197349 Fix typo. by Android Partner Docs - 185069980 fix typo by Android Partner Docs - 185020036 Add example about optimizing kernel initcall by Android Partner Docs - 184942796 Add analog-to-USB-C adapter and USB device spec by Danielle Roberts - 184900015 Exclude old bulletins from localization by Danielle Roberts - 184880179 Update Feb 2018 bulletins with AOSP links by Danielle Roberts PiperOrigin-RevId: 185568049 Change-Id: Id2ddd64fd6d7f29d7d5dee0e900c84b1a69e2a55 --- en/devices/accessories/headset/usb-adapter.html | 112 ++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 en/devices/accessories/headset/usb-adapter.html (limited to 'en/devices/accessories/headset/usb-adapter.html') diff --git a/en/devices/accessories/headset/usb-adapter.html b/en/devices/accessories/headset/usb-adapter.html new file mode 100644 index 00000000..4b70bc1d --- /dev/null +++ b/en/devices/accessories/headset/usb-adapter.html @@ -0,0 +1,112 @@ + + + USB-C-to-Analog Audio Adapter + + + + + + + + +

+While some new Android phones are being produced without a 3.5 mm jack, users +may still own 3.5 mm headsets that they want to use with those devices. To +facilitate that, this article specifies a USB-C-to-analog audio adapter spec to +plug +3.5 mm headsets +into devices that only have a +USB-C port.

+This documentation specifies the minimum requirements: accessory manufacturers +are encouraged to add features while keeping these requirements in mind. +

+ +

Adapter type

+Only digital-to-analog adapters are allowed. Analog-only adapters following +USB.org's "USB Type-C Cable and Connector +Specification, Release 1.2, Appendix A" are not supported. +

Functional overview

+The adapter allows users to plug their existing 3.5mm accessories into devices +with USB-C ports. To do this, the adapter supports: +

Stereo analog devices with and without microphones
Digital to analog conversion of 2 output channels
Analog to digital conversion of 1 input channel
Detection of analog device insertion
Detection of headset microphone
Detection of output impedance
Translation of headset button events to HID events

+ +

Analog interface

+The adapter shall not present any UAC interface, playback, or capture endpoints +to the USB host until a device is inserted and properly identified. Depending on +the type of device detected, the following UAC terminal types must be reported: +

+ +

Headphones. Low impedance transducers, < 1 kiloohm, no + microphone: 0x0302
Headset. Low impedance transducers with microphone: 0x0402
Line in. High impedance input: 0x603
Line out. High impedance output: 0x604
Line in and Line out or Line in and Mic: + 0x400

+ +

Button functions

+The adapter shall convert button events received from the analog interface and +conforming to the Android +analog headset +specification to the following HID events:

+ + + + + + + + + + + + + + + + + + + + + +

Function	Mappings
A	HID usage page: 0x0C + HID usage: 0x0CD
B	HID usage page: 0x0C + HID usage: 0x0E9
C	HID usage page: 0x0C + HID usage: 0x0EA
D	HID usage page: 0x0C + HID usage: 0x0CF

+ + + + -- cgit v1.2.3