Moo Bug Is an Adorable Little Quadrupedal Robot Based on the Pico W

Robotics can be a very intimidating hobby to dive into. Even simple robots are actually quite complex—both mechanically and electronically—and they can also get very expensive. There are plenty of DIY robot kits on the market, but they usually feel more like toys and can’t do much. If you want a simple and affordable quadrupedal robot, then the adorable Moo Bug is a great choice.

Moo Bug utilizes about the simplest leg arrangement possible. It has four legs, each of which has two degrees of freedom (DoF) actuated by small hobby servo motors. Because each leg has a hip joint and knee joint, Moo Bug can scurry along forward and backwards, and also rotate clockwise or counterclockwise. The user can program the gait however they like, so there is plenty of room for fun after completing construction.

To keep the part count, cost, and weight down, Moo Bug has a clever structure in which the control board PCB doubles as the chassis. That custom PCB contains an interface for a Raspberry Pi Pico W development board and two 18650 lithium battery cells. The bottom side of the PCB has mounting holes for attaching the four hip joint servo servo motors. The legs are 3D-printable and don’t require much filament at all.

Because Moo Bug uses a Pico W (or “Pi Cow,” hence the name), users can control their robot wirelessly if they choose. They can also add on shields, like the OLED screen shield shown on the project page that can show status information or a face.

Moo Bug has limited capability, but it is affordable to build and should help you learn some of the basics of robotics so that you can move onto more robust robots later.