Can Raspberry Pi be used instead of Google Nest as a hub to control my smart home via Google Assistant?

Question

I am searching for a way to make my home "smart". I have raspberry pi 4 and pixel 2 phone. I thought that it would be cool to make my dumb devices "smart" and control them via Google Assistant from Pixel phone.

I stumbled upon this picture (source) - it describes request lifecycle, and I am wondering if it is possible to use my Raspberry Pi 4 instead of Google Nest/Smart Speaker (which is located near "JS" thing).

_{(source: google.com)}

I am a software developer and I can write any server code is needed for this, but I can't find any docs yet.

Answer 1

That diagram is describing Google Assistant's Local Control SDK.

When using the Local Control SDK you write some JavaScript that is executed on the a Google Home/Home Mini/Nest Hub to send control messages over the local network to the device you want to control. (You still need to have a full cloud setup for the local control to work as well, docs for how to write a full Smart Home Action are here)

You can build your own (for none commercial use) Smart Speaker using the Google Assistant Service library which will run on a Raspberry Pi. I do not think this supports the Local control.

Now if you want to use your phone to issue commands to Google Assistant and then just use the Pi to control the devices there are a few options.

One of them is to install Node-RED on the Pi and use a service like Node-RED Google Assistant Bridge (full disclosure I run this service). This lets you define virtual device that will be added to your Google Assistant and you can then connect those to what ever devices you want.