Detecting shapes and gestures has traditionally been performed by camera systems due to their large arrays of pixels. However, Jean Peradel has come up with a method that uses cheap time-of-flight (ToF) sensors to sense both objects and movement over time. Better yet, his entire project is housed within a 3D-printed “Grumpy Hedgehog” that contains not only the sensors, but a highly-interactive 1.44” LCD screen as well.
The goal with this project was to create a smart home companion, which is capable of sensing several different kinds of movements and patterns to perform a wide variety of actions such as sending keystrokes to a PC, controlling a light, or moving a servo motor. This is accomplished by taking VL53L1X ToF modules, which have a 16×16 scanning array and communicate over the I2C bus. Once the attached Arduino MKR WiFi 1010 has read this data, it can determine if the object (which appears closer on the grid) has moved up, down, left, or right.
In order to make this project a bit more friendly, Peradel designed a small enclosure/stand that houses the VL53L1X near the base. Near the top is a small LCD which shows animated hedgehog faces, the “sensor’s view” of the object, and the associated action being taken.
You can read more about the Grumpy Hedgehog gesture sensor here on Hackaday.io.