Hardware Features

For an overview of functionality, see the ST1 Fact Sheet.

The ST1 is a head-mounted display (HMD) that has the following features:

  • 640x400 see-thru display

  • 9 DOF Head-tracking, with sensor fusion to give orientation in quaternions

  • Microphone (exposed as USB device)

  • 5MP Camera (ST1-C only), exposed as UVC camera

High-Level Block Diagram


You will often see “HMD” (Head Mounted Display) and “HUD” (Heads Up Display) used interchangeably. They mean the same thing.

SDK Download

Latest Release

SDK Version



Release Date





The Six15 ST1 app is released asynchronously from our SDK releases.

It can be found on the Google Play Store, or directly downloaded and installed.

Past Releases

SDK Version



Release Date

























SDK Interfaces

There are 3 main ways to use the ST1’s display.

  1. Run Screen Mirroring using the provided applications.

  2. Send text based interfaces or static images to the display using the Intent Interface.

  3. Fully integrate ST1 into your Android app using the AIDL Interface.

There are 2 main ways to use the ST1’s camera.

  1. Use the AIDL Interface to setup and receive images from the camera.

  2. Control the camera yourself using the USB Video Class (UVC) protocol.

Access the microphone through your OS like a normal USB mic.

Android Device Compatibility

The Six15 ST1 app, (aka Six15 Service) is supported back to Android 5.0 (Lollipop).

minSdkVersion 21

The Six15 Service either targets Android 12 or Android 8.1, but your app can target any version.

targetSdkVersion 32
targetSdkVersion 27

Some versions of Android 10 (SDK 29) have a bug which broke USB permissions if the running app uses targetSdkVersion 28 or above. Google does not allow Play Store distribution of apps targeting less than SDK 29. For this reason, the version of our Six15 ST1 service inside the SDK targets a different version that the one on Google Play. The SDK service targets SDK 27 for best hardware compatibility. The Google Play service targets SDK 30+ for Google Play compatibility. Some devices running Android 10 have patched this bug. This includes all Zebra TC devices. Device running other versions of Android don’t have this issue. If this bug affects your host device the Six15 ST1 app automatically detects the problem and explains whats going on.

Devices must support USB 2.0 in Host mode (OTG). This is very common, but not universally supported on very old devices. For example, the Nexus 4 does not support host mode. The Android emulator does not support USB Host mode.

    android:required="true" />

Alternatively you could use required=”false” and dynamically detect support at runtime.

boolean supportsUsbHost = getPackageManager().hasSystemFeature(PackageManager.FEATURE_USB_HOST);

Provided Apps

Most of the apps which are part of our SDK release are intended to installed by sideloading. For instructions on sideloading apps, see APK Installation.

The Six15 ST1 service app can also be downloaded from the Google Play Store.

Six15 ST1 App

The “Six15 ST1” service app exposes both the AIDL Interface and Intent Interface.

It has built in toggles for:

  1. Screen mirroring (which exposes a cropping feature)

  2. Presentation (virtual display) mode

  3. The Intent Interface

It also has a settings screen to control various features:

  1. Set your Device’s Name

  2. Display brightness

  3. Default compression quality

  4. Camera mode (SDK or UVC)

  5. Microphone mode (enabled or disabled)

It also includes features for IMU Calibration and Firmware Update which are also available in their respective standalone apps.

We currently have 3 variants of the “Six15 ST1” service app.

Six15 ST1 Variants

Six15 ST1 Slim

Six15 ST1 Full

Six15 ST1 Google Play

Distribution Method


SDK or direct download

Google Play Store

Setup Instructions

Available in Settings

Shown during setup or in Settings

Shown during setup or in Settings

Demo Content


Picking demo, camera

Picking demo, camera

Target Audience

Custom Deployments

Users desiring best compatibility

Users desiring automatic updates and convenience

Android 10 USB Limitation



May have issues on unpatched devices

For the warehouse picking demo, the example barcodes are located here.

Demo App Slideshow Demo App Slideshow

Demo App

The demo app is a general purpose app that shows basic functionality of the ST1. Features include:

  • Displaying a slideshow on the HMD.

  • Viewing the output of the IMU/Head Tracker using a 3d visualization or graphs.

  • Testing the microphone.

  • Stream ST1 camera onto phone display.

  • Stream phone camera on ST1 display.

Demo App Slideshow Demo App Slideshow

IMU Calibration App

This app can be used to run the IMU self calibration sequence.

This functionality is also included in the Six15 ST1 app.

IMU Calibration App Start Screen IMU Calibration App Gyro Calibration IMU Calibration App Gyro Calibration Complete IMU Calibration App Mag Calibration

Updater App

This app can be used to update firmware on a ST1 device.

This updater app contains the firmware binary for the ST1. The firmware may update with each SDK release.

This functionality is also included in the Six15 ST1 app.

Updater app main screen Updater app permission dialog Updater app, update start Updater app, update in progress