Google’s kit for building a voice-controlled virtual assistant using a Raspberry Pi is back on sale, after the first batch sold out within hours.

The AIY Voice Kit, which transforms the Pi 3 into a Google Assistant and was made available with the MagPi magazine in May, is now available to pre-order in the US.

When completed, the $25 kit offers a rudimentary alternative to the Google Home or Amazon Echo smart speakers, both of which retail for more than $100. It will be capable of various tasks, including detecting hotwords, understanding natural language and responding to voice commands. Technically savvy users can extend the speaker’s capabilities to understand broader vocabularies, using TensorFlow, Google’s open source machine learning framework.

The Google Artificial Intelligence Yourself (AIY) kit includes two Voice HAT (Hardware Attached on Top) boards, which slot on top of the Pi and add two stereo mics for picking up voice commands. Also included are a speaker, the necessary wires, a cardboard case, a large arcade button and a lamp. An online guide walks users through how to build the assistant and how to link it to the Google Assistant SDK and Google Cloud Speech API that handle commands.

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“Our goal with AIY Projects has always been to make artificial intelligence open and accessible for makers of all ages,” says Bill Rutledge, director of AIY Projects at Google, who added that Google is planning to release more AIY kits.

“The positive reception to Voice Kit has encouraged us to keep the momentum going with more AIY Projects. We’ll soon bring makers the “eyes,” “ears,” “voice” and sense of “balance” to allow simple, powerful device interfaces.”

Linking its virtual assistant to the Raspberry Pi 3 seems to be a smart move by Google, as it attempts to match the popularity of Amazon’s virtual assistant Alexa. More than 14 million Raspberry Pi boards have been sold, providing a large base of technically minded users for Google to tap into.

The first batch of AIY Voice Kits have already led to some inspired creations, including the 1986 Google Pi Intercom, which packs a Google voice-assistant into a 30-year-old intercom. More AIY project creations are on show at, using the #AIYprojects hashtag.

The Voice Kit is currently available to pre-order from Micro Center in the US, and will be available in Micro Center stores by October 28th. The kit is available without the Pi 3 for $24.99 or is available for free alongside a Raspberry Pi 3 Model B for $35.

Rutledge says the AIY Voice Kit will be rolled out globally later this year.

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