The Case of the Smart Magnifying Glass

Everyone has heard of smart glasses by now, but have you heard of a smart magnifying glass? Me either, but YouTuber LeviathanEngineering decided to make smart magnifying glasses a reality. Why in the world would anyone want to do that, you ask? To become a real-life Sherlock Holmes, of course. Who wouldn’t want to have the superhuman ability to examine minute details and solve complex mysteries that puzzle even the sharpest minds at just a glance?

Becoming a MacGyver of reasoning is no small accomplishment, so how did LeviathanEngineering pull this off? Elementary, my dear Watson — artificial intelligence. Using the power of a multimodal large language model (LLM), anyone can notice tiny details and chain them together into a complex web of interconnections. Even Watson could be a Holmes if the stories were written today.

The magnifying glass itself (which does not actually do any magnifying) was 3D printed. A Raspberry Pi Zero 2 W single-board computer and a Raspberry Pi Camera Module 2 were hotglued to the print, along with a push button. The camera looks through where the lens of a real magnifying glass would be, and snaps a picture when the button is pressed.

The picture is sent to Google’s Gemini 2.0 Flash LLM, along with a prompt instructing it to analyze the scene like a detective and make Sherlock Holmes-style inferences about what it sees. When the result is returned, it is processed by the eSpeak speech synthesizer, and the audio that is generated is played with a Bluetooth speaker.

While the magnifying glass form factor and Sherlock Holmes theme are an interesting novelty, this simple and inexpensive setup could be used in a variety of other projects as well. For about $30 in parts and an hour or two of development time, the same basic approach could be used to add some serious visual intelligence to any project. So even if you are not interested in detective work, this project is well worth bookmarking for later.