Petoi Nybble: The Lightest, Fastest Walking Robotic Cat – Indiegogo Launch Oct 22

Hi, I'm Rongzhong from Pittsburgh. Eight months after my first post on OpenCat, I'm excited to announce the upcoming Indiegogo launch of Nybble, the world's lightest and fastest walking robotic cat. The campaign starts Monday, Oct 22, and you can find updates on my Twitter @PetoiCamp and on Petoi.com.

We’re counting on your support to keep this project full‑time. Subscribe, share, and if you’re a maker, help teach Nybble new tricks and bring more fun to people worldwide.

What is Nybble?

Nybble is an optimized, kitten‑sized version of the original OpenCat. It’s built on an Arduino‑compatible micro‑controller that stores instinctive “muscle memory” to drive smooth walking. For those who want perception and decision‑making, an optional AI chip – such as a Raspberry Pi – can sit on Nybble’s back. With short commands like walk or turn left, you can direct Nybble to move in any direction.

Key Features

• Lightweight: Designed to be the lightest walking robotic cat.
• Fast: Capable of agile, natural gait patterns.
• Modular: Optional AI module, programmable via Arduino IDE, Bluetooth UART, or serial.
• Soft body: Springs absorb impact, ensuring safe operation.
• Open source: Firmware on GitHub, hardware plans available upon completion.

Hardware Overview

The core controller is an ATmega328P running at 20 MHz, the same chip found in the Arduino Uno. An external 8 KB I2C EEPROM stores additional skills. NyBoard V0 consolidates power management, communication ports, and an external power supply for the optional Pi.

Assembly Guides

Detailed instructions for the head group and torso group are included in the kit. A screw‑free wooden frame, inspired by traditional Chinese woodworking, keeps the assembly intuitive. Animations will be released once shipping begins.

Soft Body & Shock Absorption

Nybble’s joints use compression springs that dampen collisions. This design keeps the robot safe when interacting with people or pets.

Circuit Diagram

The system follows a master‑slave architecture. The ATmega328P handles adaptive motion, while higher‑level commands can be sent from a Raspberry Pi or other host via serial or Bluetooth.

Communication Options

Without an optional Pi, Nybble listens for commands from the Arduino IDE or a Bluetooth UART module. For example, sending m8 30 rotates joint 8 to 30°, and kwkL triggers the “walk left” skill.

NyBoard V0

Designed by Jian Yu, NyBoard V0 streamlines wiring and future upgrades. It includes tunable power outputs, a 2×5 socket for Pi connections, and a jumper to switch I2C masters. The board also monitors battery level.

Joint Tuner

Calibration is essential for precise gait. The built‑in tuner allows you to adjust joint angles while Nybble is in calibration mode, ensuring consistent performance.

Kit Contents

The kit includes the main frame, motors, electronics, an FTDI‑to‑USB converter, and the NyBoard V0. Consumables such as the mini‑USB cable, two 14500 3.7 V Li‑ion batteries, and a smart charger are not included – they can be sourced separately. We recommend EBL 800 mAh batteries for reliable operation.

Programmable Gaits and Behaviors

After assembly, you’ll need basic programming skills to upload firmware and tune the robot. Advanced users can extend Nybble with new behaviors or integrate machine‑learning models.

OpenCat Framework

OpenCat has evolved over 2½ years from a Raspberry Pi prototype to a full modular platform. It remains open source, allowing developers to experiment with dynamic balancing and motion planning.

Timeline & Call to Action

Since moving to Pittsburgh and joining Factory Unlocked – a product‑commercialization hub – I’ve dedicated the past eight months to refining Nybble. Your support will decide its future. Join the Indiegogo campaign, share with friends, and help us bring this groundbreaking robotic cat to life.

For more technical details, join our invitation‑only Slack group by emailing [email protected]. Open issues can be posted on GitHub.