Virtual assistants, like Alexa, Siri, Google Assistant, and Cortana, are now commonplace. They’re great at quickly answering questions and controlling simple internet-connected devices, like music players. But they are far from perfect — especially when it comes to privacy concerns. Some virtual assistants, like Mycroft, prioritize privacy. But it is also possible to build your own, like the Maria anime-themed holographic virtual assistant created by Jess Peter.
Maria can perform many of them same functions as other virtual assistants that you’ve used, including controlling music playback, providing weather information, and setting timers. But the standout feature is the “holographic” display, which shows a small anime-style representation of Maria. Of course, this isn’t a true holographic display — whether that technology exists or is even possible is still debatable, as current holographic displays don’t exactly match the sci-fi vision. Instead, this uses transparent acetate plastic to reflect the image from a conventional LCD screen. It may not be a real hologram, but it does look like Maria is floating in midair.
That LCD screen is a 3.2” 800x400 model that connects to a Raspberry Pi 4 Model B via HDMI. The Raspberry Pi handles the virtual assistant tasks. It uses Google Cloud services to take care of the speech-to-text and text-to-speech, which interpret voice commands and render responses, respectively. Maria also uses the WeatherAPI and Spotify’s API to check the weather and control music playback. It listens for voice commands through a small USB microphone and plays responses through an external USB stereo speaker.
Maria resides inside of a simple 3D-printed enclosure. The design is minimal, but it is important for the functionality of the holographic display. Maria uses the Raylib library to animate the graphic representation on the screen, which reflects off of acetate sheets held at specific angles by the 3D-printed frame. If you want to design you own enclosure, you must place those acetate sheets at a similar distance and angle for the holographic display to work as intended.
While Maria may not be quite as capable as the big name virtual assistants, it does have an aesthetic that the competition just can’t match and that may appeal to you!