This sample shows how to call the Google Assistant API from Android Things using the AIY Projects Voice Kit.

It records a spoken request from the I2S microphones, send it to the Google Assistant API and plays back Assistant's spoken response on the speaker connected to the I2S DAC.

• Android Studio 2.2+
• Raspberry Pi 3
• Assembled AIY Projects Voice Kit
• Android Things Raspberry Pi Dev Preview 3.1 image with I2S enabled.

  • mount the sdcard image

    # replace sdb1 with the sdcard reader device.
    mount /dev/sdb1 /mnt/disk
    

  • edit config.txt

    # comment or remove this line:
    # dtoverlay=pwm-2chan-with-clk,pin=18,func=2,pin2=13,func2=4
    #
    # uncomment or add this line:
    dtoverlay=generic-i2s
    

  • umount the sdcard image

    sync
    umount /mnt/disk
    

• Google API Console Project with Google Assistant API enabled.
• OAuth client ID with application type Other
• Google Account with the following activity controls enabled
  • Web & App Activity
  • Location History
  • Device Information
  • Voice & Audio Activity

• Get the client_secret_NNNN.json OAuth client ID JSON file for the application from Google Developer Console credentials section

• Using the oauth2l command line tool generate a REFRESH_TOKEN

     oauth2l --json client_secret_NNNN.json token \
        https://www.googleapis.com/auth/assistant-sdk-prototype
  

• Edit Credentials.java:

  • From the client_secret_NNNN.json file copy:
    • CLIENT_ID
    • CLIENT_SECRET
  • From the oauth2l token command line tool output copy:
    • REFRESH_TOKEN

• On Android Studio, click on the "Run" button or on the command line, type:

./gradlew installDebug
adb shell am start com.example.androidthings.assistant/.AssistantActivity

• Press the button: recording starts.
• Ask a question in the microphone.
• Release the button: recording stops.
• The Google Assistant answer should playback on the speaker.

Copyright 2017 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

http://www.apache.org/licenses/LICENSE-2.0

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.