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Bug: 79346240
Change-Id: Ic471df2f181e4611b37459955c3aa03a8c2456d5
Signed-off-by: Dave Smith <>
Latest commit b37571a May 19, 2018

Bluetooth GATT Server Sample (Kotlin)

This application demonstrates accessing the BluetoothGattServer Android API from within an Android Things application. The sample application advertises the Current Time Service, and implements the server role of the GATT Time Profile.


  • Android Things compatible board
  • Android device running Android 4.3 (API 18) or later
  • Android Studio 2.2+

Getting Started

  1. Import the project using Android Studio and deploy it to your board. The sample will automatically enable the Bluetooth radio, start a GATT server, and begin advertising the Current Time Service.
  2. Install the Android BluetoothLeGatt client sample on your Android mobile device.
  3. Use the client app to scan and connect to your Android Things board, and inspect the services and characteristics exposed by the GATT server.
  4. Read the value of the Current Time characteristic (0x2A2B).
  5. Register for notifications on the Current Time characteristic. The client receives an update once per minute with the latest time.
  6. Manually set the time on your board. The time change triggers a notification to the client.

Setting the Time

You can set the system clock date/time manually on your Android Things board with the date shell command over ADB. By default, the command accepts a new date in the format:

# Reboot ADB into root mode
$ adb root

# Set the date to 2017/12/13 12:00:00
$ adb shell date 123112002017.00

Setting the Time Zone

You can set the system time zone manually by updating the persist.sys.timezone system property over ADB.

# Reboot ADB into root mode
$ adb root

# Set the time zone to US Mountain Time
$ adb shell setprop persist.sys.timezone "America/Denver"

Enable auto-launch behavior

This sample app is currently configured to launch only when deployed from your development machine. To enable the main activity to launch automatically on boot, add the following intent-filter to the app's manifest file:

<activity ...>

        <action android:name="android.intent.action.MAIN"/>
        <category android:name="android.intent.category.HOME"/>
        <category android:name="android.intent.category.DEFAULT"/>



Copyright 2018 The Android Open Source Project, Inc.

Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

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