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DIVA - DIVersely Assisted

Added to IoTplaybook or last updated on: 08/05/2019
DIVA - DIVersely Assisted



The Google Assistant is powerful and can help users in many ways. The most common ways to interact with the Google Assistant are through speech and text; however, not all users are able to interact with the Google Assistant using their voice or typing. Voice and text are also not the best ways to communicate with the Google Assistant in all scenarios.

To help in those situations, we created a device that lets users trigger commands to the Google Assistant pressing a button or using RFID/NFC tags that can be attached to physical objects. To create the device, we leveraged a Google AIY Voice Kit and had some fun hacking the solution.

Learn more about the idea behind the DIVA project in our publication.

At the moment this approach is letting Giovanni, brother of one of us, affected by Down Syndrome, almost blind and not able to speak, gain autonomy on starting entertainment content on his TV and speakers.

We hope it can also be used to help other people with disabilities to gain autonomy in their daily tasks.

    Things used in this project

    Hardware components

    AIY Voice
    Google AIY Voice
    × 1  Info
    RFID reader (generic)
    × 1


    The idea is to create a device that:

    • Waits for the button to be pressed or an RFID tag to be tapped
    • Retrieves the command associated with the button or with the specific RFID tag
    • Send the command to the Google Assistant
    • Reproduces the answer provided by the Assistant

    1. Prerequisites

    Have a working Google AIY Voice kit connected to the Internet. Follow the Google AIY Voice kit instructions till the end, when you run the Demo.

    Please double check your Google AIY Voice kit is able to run the following script:


    This is the script that will create the following configuration files that we will use in the script:


    If you can’t run the script or you can’t see the 2 files listed above, please check you completed all steps in the instructions.

    2. Hardware Components

    The project requires few hardware elements:

    • Google AIY Voice Kit
    • USB RFID reader
    • RFID tags

    and it is easy to assemble. Just connect the RFID reader to the Google AIY Voice Kit via the Raspberry Pi 3’s USB port. When it detects an RFID tag, the RFID reader will send the TAG ID to the kit as a string of text, just like a keyboard.

    DIVA device hardware setup
    DIVA device hardware setup

    3. Script

    Next, we’ll create a script that:

    • Initializes and starts the Assistant
    • Accepts text input as a command for the Assistant (the USB RFID reader sends TAG IDs to the Pi as if they were typed by a USB keyboard)
    • Checks if the text is associated with a command configured in the script
    • Sends the command to the Google Assistant SDK instance
    • Reproduces the answer provided by the Google Assistant SDK instance on the speaker of the device.

    Start by opening a new script called '’ using your preferred text editor, for example, nano:

    pi@raspberrypi:~ $ nano

    Copy and paste the script attached '' into your file. Then configure the COMMANDS object as a mapping between the ID of the RFID TAG(s) you are planning to use and the corresponding text command you want to send to the Assistant.

    To test the script you may try commands like :

    • What is the weather like?
    • Tell me a joke, please
    • Play YouTube video on my TV

    4. Run the script

    From the terminal, we can make the script executable:

    pi@raspberrypi:~ $ chmod +x 

    And execute the script:

    pi@raspberrypi:~ $ ./
    device_model_id: DEVICE_MODEL_ID
    device_id: DEVICE_ID
    Say "OK, Google" then speak, write a command, press the button or tap a card.
    Press Ctrl+C to quit...

    Feel free to create RFID tags to play your favorite music, control your light, or check your room temperature:

    DIVA device working with RFID cards
    DIVA device working with RFID cards

    Once you have your tags configured, you can attach them to plushes to start your favorite cartoons, or to your CDs cases to create your own music jukebox.


    This project was a fun experience and we created something useful for at least one person with disability. We hope you will enjoy this project and that it may help other people with disabilities.

    We’d like to continue to iterate on this, and we see several options to improve this project.Some ideas are:

    We would appreciate any feedback or suggestions on what to prioritize, please leave a comment below.

    Code Python Download the code

    #!/usr/bin/env python3
    # Copyright 2017 Google Inc.
    # You may obtain a copy of the License at
    # See the License for the specific language governing permissions and
    # limitations under the License.
    import argparse
    import json
    import logging
    import os
    import pathlib2 as pathlib
    import platform
    import sys
    import subprocess
    import threading
    import google.oauth2.credentials
    from aiy.board import Board, Led
    from google.assistant.library import Assistant
    from google.assistant.library.event import EventType
    from google.assistant.library.file_helpers import existing_file
    from google.assistant.library.device_helpers import register_device
       format="[%(asctime)s] %(levelname)s:%(name)s:%(message)s"
    COMMANDS = {}
    # Configure here the command you want to associate to the button
    COMMANDS['BUTTON'] = "Tell me a joke"
    # Configure here the RFID TAG ID with the associated command
    COMMANDS['TAG_ID_1'] = "Play YouTube videos on my Chromecast"
    COMMANDS['TAG_ID_2'] = "Play Pop Music from Google Play Music on my Chromecast"
    class DivaAssistant(object):
     def __init__(self, credentials_file, device_config):
       self._assistant = None
       self._board = Board()
       self._device_config = device_config
       self._can_start_conversation = False
       self._credentials_file = credentials_file
       self._task = threading.Thread(target=self._run_task)
     def start(self):
       """Starts the Assistant event loop and begin processing events."""
       self._board.button.when_pressed = self._on_button_pressed
       self._task.daemon = True
     def _on_button_pressed(self):
       query = COMMANDS.get('BUTTON', 'Repeat after me, Not configured')
     def _run_task(self):
       """Starts the Assistant.
       Retrieve Credentials, Device Configuration and start the assistant.
       with open(self._credentials_file, 'r') as f:
         self._credentials = google.oauth2.credentials.Credentials(token=None,
       with open(self._device_config, 'r') as f:
         id_data = json.load(f)
         self._device_id = id_data["device_id"]
         self._device_model_id = id_data["model_id"]
       with Assistant(self._credentials, self._device_model_id) as assistant:
         self._assistant = assistant
         print('device_model_id:', self._device_model_id + '\n' +
               'device_id:', self._device_id + '\n')
         for event in assistant.start():
     def _process_event(self, event):
       """Process the event from the Assistant."""
       if event.type == EventType.ON_START_FINISHED:
         self._can_start_conversation = True
         self._board.led.status = Led.BEACON_DARK  # Ready.
         if sys.stdout.isatty():
           print('Say "OK, Google" then speak, write a command, press the button or tap a card. '
                 'Press Ctrl+C to quit...')
       elif event.type == EventType.ON_CONVERSATION_TURN_STARTED:
         self._can_start_conversation = False
         self._board.led.state = Led.ON  # Listening.
       elif event.type == EventType.ON_END_OF_UTTERANCE:
         self._board.led.state = Led.PULSE_QUICK  # Thinking.
       elif (event.type == EventType.ON_CONVERSATION_TURN_FINISHED
             or event.type == EventType.ON_CONVERSATION_TURN_TIMEOUT
             or event.type == EventType.ON_NO_RESPONSE):
         self._board.led.state = Led.BEACON_DARK  # Ready.
         self._can_start_conversation = True
       elif event.type == EventType.ON_ASSISTANT_ERROR and event.args and event.args['is_fatal']:
     def send_text(self, message):
       """Send text massage to the Assistant."""
       if self._can_start_conversation:
         print('Sending to the Assistant message: %s' % message)
    def main():
     parser = argparse.ArgumentParser(
     parser.add_argument('--credentials', type=existing_file,
                         help='Path to store and read OAuth2 credentials')
     parser.add_argument('--device_config', type=existing_file,
                         help='The file containing device model ID registered')
     args = parser.parse_args()
     # initialize and start the Assistant
     assistant = DivaAssistant(args.credentials, args.device_config)
     # accept keyboard inputs
     while True:
       # wait for keyboard input
       message = input()
       # check if the message is registered as command in
       # the COMMAND variable
       message = COMMANDS.get(message, message)
       # send message to the Assistant
    if __name__ == '__main__':


    Lorenzo Caggioni

    Lorenzo Caggioni

    1 project • 2 followers


    Paolo Pigozzo

    Paolo Pigozzo

    1 project • 2 followers


    Davide Ferraro

    Davide Ferraro

    0 projects • 1 follower


    Thanks to Egil Hogholt, Teresa Pato, and Thomas Riga.


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    This article was originally published at It was added to IoTplaybook or last modified on 08/05/2019.