Blog post: http://nilhcem.com/android-things/create-your-google-assistant-robots

• Connect an LED to BCM25 (pin #22)
• Connect a button to BCM23 (pin #16)
• Connect a Servo to PWM0 (pin #12)
• Connect an LED Matrix to SPI0.0 (DIN to MOSI (pin #19), CS to SS0 (pin #24), CLK to SCLK (pin #23), VCC to 5V, GND to Ground)
• Connect a USB microphone
• Connect an audio speaker

For readability, the app is composed of 3 gradle modules and 1 google cloud functions directory

• :app: Android Things Kotlin application
• :events-pubsub: Subscribes to Pub/Sub via gRPC to return events in a LiveData object
• :google-assistant: Google Assistant
• cloud-functions: Google Cloud Functions directory

• Create a new project from the Google Developers Console
• Install the Google Cloud SDK and enable Google Cloud Functions API (quickstart guide)
• Locate your project ID in the dashboard and note for later use. (Read here for help)
• Enable the Pub/Sub API (Read here for help), and create a topic named "PubSubMessages and a subscription named "PubSubMessagesSub":

gcloud init
gcloud beta pubsub topics create PubSubMessages
gcloud beta pubsub subscriptions create --topic PubSubMessages PubSubMessagesSub

• Generate a JSON service account key (name=androidthings-pubsub), with the Pub/Sub Subscriber role, and save it to events-pubsub/src/main/assets/service-account.json

• Update "your-google-project-id" on line 4 of cloud-functions/index.js.
• Update GOOGLE_PROJECT_ID value in events-pubsub/src/main/java/com/nilhcem/assistant/androidthings/pubsub/EventLiveData.java.

• Deploy the webhook function with the following command

cd cloud-functions
gcloud beta functions deploy webhook --stage-bucket staging.<PROJECT ID>.appspot.com --trigger-http

• This script will deploy the function to Google Cloud and give you the endpoint address. Keep the address somewhere, you'll need it (something like https://us-central1-<PROJECT ID>.cloudfunctions.net/webhook).

• Create an api.ai project
• Import the ApiAi_ShoeboxRobot.zip file
• Go to the Fulfillment tab, update the webhook address, and set basic auth (name=shoebox, pass=robot)

• Enable the Google Assistant API and create an OAuth Client ID (name=androidthings-googleassistant) (Read here for help)
• Download the client_secret_NNNN.json file from the credentials section of the Console
• Use the google-oauthlib-tool to generate credentials:

pip install google-auth-oauthlib[tool]
google-oauthlib-tool --client-secrets client_secret_NNNN.json \
					 --credentials ./google-assistant/src/main/res/raw/credentials.json \
					 --scope https://www.googleapis.com/auth/assistant-sdk-prototype \
					 --save

• Make sure to set the Activity Controls for the Google Account using the application.

• On the first install, grant the sample required permissions for audio and internet access:

./gradlew assembleDebug
adb install -g app/build/outputs/apk/app-debug.apk

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

adb shell am start com.nilhcem.assistant.androidthings/.ui.main.MainActivity

• Try the assistant demo:

  • 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.