If you're looking for a last-minute Halloween wearable to impress your friends, you've got to check out this awesome Remy, from the movie "Ratatouille", created by engineer, maker, and developer Christina Ernst aka shebuildsrobots over on Instagram. Using an Adafruit Metro Mini, this little robotic rat can be worn on your head and appears to control your every movement by tugging at your hair. That said, we think it could be easily recreated using a Raspberry Pi Pico with a little tweak to the code.
The Remy figure was designed by Ernst and is made to be 3D printed. The hollow design makes it lightweight, and easy to mount to a hidden headband so that it can be perched right on top of your head, just like the movie. Remy's hands have holes for your hair to pass through and are moveable thanks to a couple of hobby servos.
Since this is meant to be worn on your head, form factor is an important consideration. Ernst opted to use two sub micro servos to control the arms as they're much smaller and lighter than regular servos. You could upgrade them to full sized servos but some modification to the body would be necessary to make them fit.
According to Ernst, Remy's arms are attached to the sub micro servos by hot gluing floral wire to them through one of the servo arm holes. She also added bigger loops around his hands to fit more hair. The arms are programmed to move randomly instead of on a fixed loop. But Ernst also supplied code for using an accelerometer connected to Adafruit Metro Mini as a means of input. The Adafruit Metro Mini is an Arduino compatible board with an ATmega328 CPU running at 16 MHz. You could use other boards in its place like a Raspberry Pi Pico or the new Raspberry Pi Pico 2. The accelerometer is an MPU6050 which uses I2C for communication. It only controls Remy's right arm, but an additional sensor, or some clever math could see both of Remy's arms being gesture controlled. However, the random movement would be an easier and convincing means to have Remy control your culinary tasks. You can use any budget 3D printer to reproduce the body but Ernst happened to use an Elegoo Neptune 4 Pro—a printer we gave a glowing 4.5/5 star review to.
Ernst was kind enough to make this project entirely open source for personal use so you can make it yourself at home. She's provided all of the STL files you need to print along with all of the source code she created to bring Remy to life over at GitHub.
If you want to see this Raspberry Pi project in action, you can check it out over at Instagram and read more details about its construction at the GitHub link mentioned above.
