Turn a Rotary Phone Into a Google Home

Virtual voice assistants can be great for setting appointments, turning lights on or off, or attaining random facts. What if, however, you could just pick up a heavy rotary phone handset and order your assistant to do your bidding with no wake word introduction? Sure, it’s not that different, but would give a nice tactile feel to the operation – like you’re really in command of the situation.

Setting up such a system hardware-wise is actually fairly easy, as outlined in this project write-up. Here a Raspberry Pi Zero W is implemented to run Google assistant, with a USB audio adapter used to connect to the headset's microphone and speaker. The hook switch is wired to the Pi’s GPIO 18 pin and ground. This substitutes in for “Hey Google” as a wake command when you pick up the receiver, allowing you to simply utter your demands with no preface. While it would take a bit of fiddling to get the connections right, rotary phones are typically quite basic from an electronic standpoint, so this shouldn’t be prohibitive.

The tough part of the build seems to be is actually configuring Google Assistant on the Pi. A good portion of the instructions are dedicated to this operation, so while it might be intimidating, at least it’s well documented. Besides human interaction, this also involves hours of compilation time, so you may want to leave it running overnight.

After that bit of yak shaving, though, you'll have a really excellent Google Assistant user interface. Perhaps at some point you could even integrated the dial itself!