Smart Room

doorbell

The Android Things Doorbell sample demonstrates how to create a “smart” doorbell. The sample captures a button press from a user, obtains an image via a camera peripheral, processes the image data using Google’s Cloud Vision API, and uploads the image, Cloud Vision annotations and metadata to a Firebase database where it can be viewed by a companion app.

How camera works

Schematics

Pre-requisites

• Android Things compatible board
• Android Things compatible camera (for example, the Raspberry Pi 3 camera module)
• Android Studio 2.2+
• Google Cloud project with Cloud Vision API enabled
• Firebase project with Database and Storage
• The following individual components:
  • 1 push button
  • 1 resistor
  • jumper wires
  • 1 breadboard

Setup and Build

To setup, follow these steps below.

1. Add a valid Google Cloud Vision API key in the constant CloudVisionUtils.CLOUD_VISION_API_KEY

• Create a Google Cloud Platform (GCP) project on GCP Console
• Enable Cloud Vision API under Library
• Add an API key under Credentials
• Copy and paste the Cloud Vision API key to the constant in CloudVisionUtils.java

2. Add a valid google-services.json from Firebase to app/ and companionApp/

• Create a Firebase project on Firebase Console
• Add an Android app with your specific package name in the project
• Download the auto-generated google-services.json and save to app/ and companionApp/ folders

3. Ensure the security rules for your Firebase project allow public read/write access. Note: The rules in this section are set to public read/write for demonstration purposes only.

• Firebase -> Database -> Rules:

    {
      "rules": {
        ".read": true,
        ".write": true
      }
    }
  

• Firebase -> Storage -> Rules:

    service firebase.storage {
      match /b/{bucket}/o {
        match /{allPaths=**} {
          allow read, write;
        }
      }
    }
  

There are two modules: app and companionApp, the former is on device while the latter on companion device e.g. Android phone.

Running

To run the app module on an Android Things board:

1. Connect a push button to your device's GPIO pin according to the schematics below
2. Deploy and run the app module
3. Take a picture by pushing the button
4. Verify from Firebase Console that pictures are uploaded to a log in the Firebase database of your project
5. Verify from Firebase Console that the uploaded pictures in the log get annotations after a small delay from the GCP Cloud Vision

To run the companionApp module on your Android phone:

1. Deploy and run the companionApp module
2. Verify that you see a new annotated picture every time you push the button

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 ...>

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

</activity>