This Raspberry Pi ghost talks to trick-or-treaters using AI

It’s not too late to put together a spooky Raspberry Pi-powered Halloween project, and we’ve got a cool one to share today that’s sure to inspire your inner maker. This one comes to us from maker and developer Nathan from NathanBuildsDIY, who’s created a really cool Pi-powered AI ghost named Casper that talks to trick-or-treaters.

Much like the ghost he’s named after, this ghost is light-hearted and friendly instead of scary. According to Nathan, the idea was to create an interactive ghost who could talk back and forth with trick-or-treaters as they approached the porch. Casper can detect when they’re nearby and uses AI to come up with all sorts of conversational quips, from answers to questions to Halloween-themed jokes.

Nathan shared a video showing off Casper’s creation’s ins and outs. In it, he explained that his design has four main elements. It relies on a distance sensor to look out for approaching trick-or-treaters. Once they’re nearby, a microphone listens for audio, which is translated into text. This text is then parsed through an AI system that comes up with the responses.

The main board powering this project is a Raspberry Pi 5. It’s connected to an ultrasonic sensor housed inside a cute little bowtie. A few LEDs are thrown into the mix as well, illuminating his eyes and mouth. The head features a custom 3D-printed frame that has been made open source, with STLs available for anyone to download and print at home.

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The video goes into extremely in-depth detail about the software side of the project, so we won’t give away too much. However, we’ll touch on the major components, which include Vosk for text-to-speech and Google Gemini for all of the AI processing. You can peruse the source code over at GitHub.

If you want to see this Raspberry Pi project in action, you can check it out on YouTube. There, you’ll find not just a demo but a comprehensive breakdown of its construction.