Runs the google assistant ("OK Google") on a raspberry pi.
In other words it turns your raspberry pi into a "google home" device
- speaker (or headphone) that is connected to the audio jack of the raspberry pi
- USB microphone (or webcam with microphone) that is connected to one of the USB ports of the raspberry pi.
This repository is based on the instructions specified at: https://developers.google.com/assistant/sdk/guides/library/python/
So first you need to perform the following steps of these instructions:
- Configure a Developer Project and Account Settings. Write down the Project ID generated by google as you need it in STEP 2.
- Register the Device Model - you don't need to transfer the downloaded client secret to the raspberry pi. You will need it for setting the service variable "GOOGLE_ASSISTANT_CLIENT_SECRET" in the next step. Also write down the device model ID generated by google as you will also need this in next step.
- Follow the standard instructions to create and deploy a balena application = amongst others: (fork and) clone this github repository, create the git remote for this balena application and then do a
git push balena master(or similar command) - As you have not set any service variables you will see errors in the log files.
- Set the following service variables using the balena dashboard.
| Service | Name | Description |
|---|---|---|
| google_assistant | GOOGLE_ASSISTANT_PROJECT_ID | The project ID generated by google in previous step. Don't confuse this with the project name that you have specified. |
| google_assistant | GOOGLE_ASSISTANT_DEVICE_MODEL_ID | The device model id generated by google in previous step |
| google_assistant | GOOGLE_ASSISTANT_CLIENT_SECRET | The complete client secret (= json string) retrieved in previous step |
- When the GOOGLE_ASSISTANT service is restarted you should see something like the following in the balena Logs (this also means that you can continue with the next step):
24.06.19 17:56:33 (+0200) Starting service 'google_assistant sha256:c392950370c392295ee322780bd29f97aead2dc2e1d739977b2f401b172d3c8d'
24.06.19 17:56:34 (+0200) google_assistant The credentials (/root/.config/google-oauthlib-tool/credentials.json) are not set !
24.06.19 17:56:34 (+0200) google_assistant ... Creating /client_secret.json based on the contents of device service variables GOOGLE_ASSISTANT_CLIENT_SECRET...
24.06.19 17:56:34 (+0200) google_assistant **********************************************************************
24.06.19 17:56:34 (+0200) google_assistant * You can now create the google credentials by launching the script: *
24.06.19 17:56:34 (+0200) google_assistant * /create_credentials.sh *
24.06.19 17:56:34 (+0200) google_assistant * in a balena terminal for the service 'google_assistant'. *
24.06.19 17:56:34 (+0200) google_assistant **********************************************************************
24.06.19 17:56:34 (+0200) Started service 'google_assistant sha256:c392950370c392295ee322780bd29f97aead2dc2e1d739977b2f401b172d3c8d'
- In Balena dashboard open a Terminal for the service "GOOGLE_ASSISTANT" and enter the command
/create_credentials.shYou should see something like (I partially masked it):
root@f0bc010:/# /create_credentials.sh
Please visit this URL to authorize this application: https://accounts.google.com/o/oauth2/auth?response_type=code&client_id=3983XXXXXXX84fb.apps.googleusercontent.com&redirect_uri=urn%3AietXXXXXXXh%3A2.0%3Aoob&scope=https%3A%2XXXXXXXapis.com%2Fauth%2Fassistant-sdk-prototype+https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fgcm&state=d720mXXXXXXXXXXXXXXXXXXXXXXXXXX&code_challenge=GXXXXXXXJs&code_challenge_method=SXXXXXXX6&prompt=consent&access_type=offline
Enter the authorization code:
- Copy paste above URL in a browser and follow the instructions as outlined in step 3. of Generate Credentials.
- copy paste the authorization code in the balena terminal window and you should get something like:
...
Enter the authorization code: 4/cgElC5XXXXXXXXXXXXXXXXXXXXXXXXXXXXXDe3iQ4U
credentials saved: /root/.config/google-oauthlib-tool/credentials.json
The credentials =
{"scopes": ["https://www.googleapis.com/auth/assistant-sdk-prototype", "https://www.googleapis.com/auth/gcm"], "client_id": "3983XXXXXXXXXXXXXXXXXXXXXXX.apps.googleusercontent.com", "token_uri": "https://accounts.google.com/o/oauth2/token", "client_secret": "KiXXXXXXXXXXXXXXXXXXXc7", "refresh_token": "1/oohXXXXXXXXXXXXXXXXXXXXXX4s"}
You should now restart the google_assistant service.
root@f0bc010:/#
- That is it. You can now restart the google_assistant service within the balena dashboard and you should see something like:
17.06.19 00:25:25 (+0200) Starting service 'google_assistant sha256:47e2a96dfd306851d3c4934cdf05eae46ab5d21b89c14303b44d37d5fd1c99a1'
17.06.19 00:25:26 (+0200) google_assistant Creating the /root/.config/google-oauthlib-tool/credentials.json using device service variable GOOGLE_ASSISTANT_CREDENTIALS ...
17.06.19 00:25:26 (+0200) google_assistant Starting googlesamples-assistant-hotword ...
17.06.19 00:25:26 (+0200) Started service 'google_assistant sha256:47e2a96dfd306851d3c4934cdf05eae46ab5d21b89c14303b44d37d5fd1c99a1'
17.06.19 00:25:31 (+0200) google_assistant device_model_id: pi3thrXXXXXXXXXXXXX44
17.06.19 00:25:31 (+0200) google_assistant device_id: B12XXXXXXXXXXXXX64E3
17.06.19 00:25:31 (+0200) google_assistant
17.06.19 00:25:36 (+0200) google_assistant Registering...Done.
17.06.19 00:25:36 (+0200) google_assistant
17.06.19 00:25:36 (+0200) google_assistant ON_MUTED_CHANGED:
17.06.19 00:25:36 (+0200) google_assistant {"is_muted": false}
17.06.19 00:25:36 (+0200) google_assistant ON_START_FINISHED
17.06.19 00:25:36 (+0200) google_assistant ON_MEDIA_STATE_IDLE
It is also possible to set the google credentials through the device service variable GOOGLE_ASSISTANT_CREDENTIALS.
Of course in that case you must know the google credentials.
This step is mainly there to be backwards compatible with version v1.0.0
| Service | Name | Description |
|---|---|---|
| google_assistant | GOOGLE_ASSISTANT_CREDENTIALS | The complete credentials (= json string). If this environment variable is set then the google assistant at startup will first overwrite the contents of the file /root/.config/google-oauthlib-tool/credentials.json with the contents of this variable. |
See also issues reported in this github repository (feel free to add your own issues)
If the audio jack is not plugged correctly you will hear a lot of noise. In that case move the audio jack a bit more in or out until the noise is gone.
2. ERROR "google_assistant [FATAL:audio_input_stream.cc(47)] Input device could not be opened: default"
This indicates that the default audio input stream (= microphone) is not properly configured on your raspberry pi.
You can test the speakers (audio) by running the following command in a terminal for the service "GOOGLE_ASSISTANT":
speaker-test -c2 -t wav
You can change the volume by running the command:
alsamixer