Spot Micro Quadruped

Spot Micro is a 4-legged open-source quadruped robot inspired by Boston Dynamics' Spot. Created by mike4192 in 2020, the project implements full motion control on a 3D-printed Spot Micro frame, including sit, stand, body angle, and walking gaits. Supporting libraries provide additional capabilities such as SLAM mapping using a body-mounted RPLidar.

The robot uses a Raspberry Pi 3B running Ubuntu 16.04 with ROS Kinetic. Twelve PDI-HV5523MG servos (3 per leg) drive the legs through a PCA9685 i2c servo control board. The default 8-phase gait incorporates body movement to maintain balance and stability; an alternate trot gait achieves faster walking speeds.

The 3D-printed frame originates from KDY0523's Thingiverse "Spot Micro" design (thing:3445283). This repository contributes the ROS-based motion control software, kinematics implementation, custom shoulder mounts, lidar mount, and SLAM integration on top of that frame.

Hardware

Estimated cost: $300-450 USD. Build time: 2-4 weeks. Skill level: Intermediate to Advanced (requires familiarity with ROS, Linux, and 3D printing).

Software architecture

The project is structured as a ROS Catkin workspace. Key nodes:

• spot_micro_motion_cmd — main C++ motion control node implementing kinematics, gaits, and state machine
• ros-i2cpwmboard — PCA9685 servo driver, controlled via i2c
• spot_micro_keyboard_command — Python keyboard teleop
• spot_micro_joy — joystick teleop
• servo_move_keyboard — manual servo calibration utility
• spot_micro_rviz / spot_micro_plot — visualization
• lcd_monitor — LCD status display

Firmware status

This program is BYOD (bring-your-own-device). The motion control runs on a Raspberry Pi with ROS, not on the orobot platform's native firmware. The orobot.io program here serves as a learning entry point and command interface; full hardware control requires checking out the GitHub repository, building the catkin workspace, and flashing the configured Pi image. See the project README for setup instructions.

Attribution

Source: https://github.com/mike4192/spotMicro Author: mike4192 License: MIT Frame design: KDY0523 (Thingiverse thing:3445283, separate license)

Printing

The print set is the 13 canonical SpotMicro parts from the upstream mike4192/spotMicro spot_micro_rviz/urdf/stl/ set. Because this is a 12-DOF quadruped (four identical-per-side legs), note the print quantities below — the static list shows each file once.

Body (print x1 each):

• mainbody.stl — central body shell
• frontpart.stl — front body section
• backpart.stl — rear body section
• foot.stl — base/floor plate

Left legs (print x2 each — 2 left legs):

• lshoulder.stl, larm.stl, larm_cover.stl, lfoot.stl

Right legs (print x2 each — 2 right legs):

• rshoulder.stl, rarm.stl, rarm_cover.stl, rfoot.stl

Left and right leg parts are true mirrors, not interchangeable — print two of each side for the four legs (3 servos per leg = 12 DOF). One MG-class servo (PDI-HV5523MG) goes in each joint.

Optional:

• rplidar_main.STL — RPLidar A1 mount, only needed if you add the body-mounted lidar for SLAM. Skip it for a walk-only build.

Cleanup note: the imported list previously held 39 files — the 13 real parts plus 26 duplicate re-imports that all carried opaque orobot-upload-<UUID>.stl names (each of the 13 parts was triplicated). The duplicates were verified by byte-size match against the upstream STLs and removed, leaving the clean, human-readable 13-part set. The 3D-printed frame derives from KDY0523's Thingiverse design (thing:3445283); servos, Pi, PCA9685, lidar, and battery are sourced from the BOM, not printed.