Petoi Nybble: The Raspberry Pi Cat Lover's Dream

MAKER: Rongzhong Li/ Translated by: Fun Endless

Cats are indeed a fascinating species, their fluffy appearance and soft bodies have captured the hearts of countless cat lovers.

Many people cannot keep cats due to various real-life issues, so today we bring you this 3D-printed robotic cat that can fully satisfy your desire to pet a cat.

Nybble is a project that Dr. Li Rongzhong has been carefully planning since he bought his first Raspberry Pi in 2016.

Dr. Li has been dedicated to research in the fields of STEM and AI, and from Petoi Nybble, we can see how he has cleverly integrated these two areas.

Nybble uses a laser cutter to cut various wooden components and assembles them, then uses various algorithms for training, making it increasingly resemble the behavior of a real cat, which is fun, cute, and very lively.

Among them, Nybble uses the Raspberry Pi as its brain to ponder some philosophical questions: “Who am I?” “Where do I come from?” “Where am I going?” It then issues a series of commands to the Arduino to perform detailed actions.

As a seasoned cat lover, he put a lot of effort into designing Nybble.

In the early days, Nybble’s body was built from a plastic aircraft fuselage. From the very beginning, he set the Raspberry Pi as the brain and used Arduino to control all actions.

Here is a video of Nybble’s evolution.

Now let’s enter the world of Nybble together!

Materials List

Nybble kit (crowdfunding) Arduino Pro Mini 328-5 V/16MHz Raspberry Pi 3B USB-Mini USB power cable 14500 3.7v lithium battery smart charger

Features

This cute Nybble may be the lightest and fastest robotic cat in the world. Its movement is driven by an Arduino-compatible microcontroller. It moves by storing instinctive “muscle memory”.

The Raspberry Pi installed on Nybble’s back enables it to perceive and make decisions. You can program it in your favorite language; simply send short commands like “walk” or “turn left” to guide Nybble’s movements!

Nybble is based on the OpenCat framework and features a retro wooden design that honors the craftsmanship of traditional Chinese woodworkers. It incorporates the wisdom of traditional Chinese wooden products (to honor my ancestors) to create a screw-less main frame.

Assembly Diagram

Here is a video of the assembly process, where Dr. Li provides a detailed explanation for everyone to experience:https://v.qq.com/x/page/s07960xumgs.html

Circuit Diagram

This circuit is a very traditional master-slave structure. It is suitable for the DIY version. All adaptive actions are implemented on the ATmega328P chip.

Communication with Raspberry Pi or Other Chips

Even if the kit does not include a Raspberry Pi, the code on Nybble always obeys higher-level commands. You can also send these commands to the Raspberry Pi and other chips via Arduino IDE, Bluetooth UART, or serial connection.

NyBoard V0

NyBoard V0 is designed to simplify wiring and leave room for future development. It features adjustable output, various communication and control ports, and an optimized onboard power management layout.

NyBoard is designed to avoid conflicts with all high components when installed on the Raspberry Pi. Its 2×5 communication socket accepts pins from the Raspberry Pi.

It can be powered, obey commands from the Raspberry Pi, and has a jumper switch for changing the I2C master device.

By adding a Raspberry Pi or other AI chips, you can give Nybble more talents, making it smarter, able to listen, observe, and think.

Joint Tuner

To help you tackle challenges, we also provide a nice little tool, the “L” tuner, to calibrate your Nybble.

Simply switch Nybble to calibration mode and align the observation window, input the correct calibration, and Nybble will remember them immediately.

Kit Introduction

The above image shows the Nybble kit. Isn’t it special? When I finalize each part, some components may change, such as color, length, and number of screws.

Programmable Gait and Behavior Actions

Once Nybble is assembled, basic computer skills are sufficient to upload code and adjust Nybble’s gait to a walking state.

After that, you will need higher-level skills (or learning) to appreciate the black technology behind Nybble and teach it new tricks. This involves a lot of high school mathematics!

OpenCat Framework

In the two and a half years of OpenCat’s development, the rough framework has become clearer and clearer. It started with a Raspberry Pi kit, introducing Arduino as the central pattern generator, and can be opened for any extensions/upgrades when needed.

The team has open-sourced OpenCat on Github: https://github.com/PetoiCamp/OpenCat

The source code and some architecture diagrams can be downloaded from the project repository: http://maker.quwj.com/project/82

Petoi Nybble: The Raspberry Pi Cat Lover’s Dream