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The SO-100 is a compact 6-DOF robotic arm that shares the same software interface as the SO-101. It uses Feetech STS3215 servo motors and is designed for teleoperation and imitation learning.

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Overview

The SO-100 is functionally identical to the SO-101 from a software perspective, sharing the same codebase and configuration options. The main differences are in the physical form factor and assembly.

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Features

  • 6 degrees of freedom (5 arm joints + gripper)
  • Feetech STS3215 servo motors
  • USB serial communication
  • Shared implementation with SO-101
  • Position control mode
  • Optional camera integration

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Quick Start

Since SO-100 uses the same SOFollower class as SO-101, refer to the SO-101 documentation for detailed setup and usage instructions.

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Basic Usage

from lerobot.robots.so_follower import SOFollower, SOFollowerRobotConfig

# Create configuration for SO-100
config = SOFollowerRobotConfig(
    robot_type="so100_follower",  # Specify SO-100
    id="so100_main",
    port="/dev/ttyUSB0"
)

# Use the robot
with SOFollower(config) as robot:
    obs = robot.get_observation()
    robot.send_action({
        "shoulder_pan.pos": 0.0,
        "shoulder_lift.pos": -45.0,
        "elbow_flex.pos": 90.0,
        "wrist_flex.pos": 0.0,
        "wrist_roll.pos": 0.0,
        "gripper.pos": 50.0
    })

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Configuration

The SO-100 uses the same SOFollowerRobotConfig class: 
from lerobot.robots.so_follower import SOFollowerRobotConfig
from lerobot.cameras.opencv import OpenCVCameraConfig

config = SOFollowerRobotConfig(
    robot_type="so100_follower",
    id="so100_main",
    port="/dev/ttyUSB0",
    disable_torque_on_disconnect=True,
    max_relative_target=10.0,
    cameras={
        "wrist": OpenCVCameraConfig(
            index_or_path=0,
            fps=30,
            width=640,
            height=480
        )
    },
    use_degrees=True  # For backward compatibility
)

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Motor Configuration

Identical to SO-101:
Motor NameIDModelRange
shoulder_pan1STS3215Full rotation
shoulder_lift2STS3215Limited
elbow_flex3STS3215Limited
wrist_flex4STS3215Limited
wrist_roll5STS3215Full rotation
gripper6STS32150-100%

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Differences from SO-101

From a software perspective, the SO-100 and SO-101 are identical. Both:
  • Use the same SOFollower class implementation
  • Share motor configurations
  • Support the same features
  • Use identical calibration procedures
  • Have the same API
The only difference in the code is the robot type identifier:
  • SO-100: robot_type="so100_follower"
  • SO-101: robot_type="so101_follower"
Both so100_follower and so101_follower are registered as subclasses of SOFollowerRobotConfig and use the same underlying implementation (see /home/daytona/workspace/source/src/lerobot/robots/so_follower/config_so_follower.py:45).

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Hardware Setup

Follow the same hardware setup as SO-101:
  1. Connect via USB to your computer
  2. Identify the serial port
  3. Set up port permissions (Linux):
sudo usermod -a -G dialout $USER
  1. Install LeRobot:
pip install lerobot

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Calibration

Calibration procedure is identical to SO-101: 
from lerobot.robots.so_follower import SOFollower, SOFollowerRobotConfig

config = SOFollowerRobotConfig(
    robot_type="so100_follower",
    id="so100_main",
    port="/dev/ttyUSB0"
)

robot = SOFollower(config)
robot.connect(calibrate=True)

# Follow the calibration prompts:
# 1. Move to middle position
# 2. Move through full range of motion
# 3. Calibration saved automatically
Calibration files are stored separately for each robot ID, so you can have both SO-100 and SO-101 robots with different calibrations.

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Safety Features

All SO-101 safety features apply to SO-100:

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Relative Target Limiting

config = SOFollowerRobotConfig(
    robot_type="so100_follower",
    port="/dev/ttyUSB0",
    max_relative_target=10.0  # Limit movement per step
)

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Torque Management

config = SOFollowerRobotConfig(
    robot_type="so100_follower",
    port="/dev/ttyUSB0",
    disable_torque_on_disconnect=True  # Safe shutdown
)

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API Reference

Since SO-100 uses the SOFollower class, see the SO-101 documentation for complete API details.

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Key Methods

# Connection
robot.connect(calibrate=True)
robot.disconnect()

# Observation
obs = robot.get_observation()
# Returns: dict with motor positions and camera images

# Action
action = {"shoulder_pan.pos": 0.0, ...}
sent_action = robot.send_action(action)
# Returns: actual action sent (may be clipped for safety)

# Calibration
robot.calibrate()

# Configuration
robot.configure()  # Apply PID settings, operating modes

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Teleoperation Example

Use SO-100 in a leader-follower setup: 
from lerobot.robots.so_follower import SOFollower, SOFollowerRobotConfig

leader = SOFollower(SOFollowerRobotConfig(
    robot_type="so100_follower",
    id="leader",
    port="/dev/ttyUSB0"
))

follower = SOFollower(SOFollowerRobotConfig(
    robot_type="so100_follower",
    id="follower",
    port="/dev/ttyUSB1",
    max_relative_target=15.0
))

with leader, follower:
    while True:
        obs = leader.get_observation()
        action = {k: v for k, v in obs.items() if k.endswith(".pos")}
        follower.send_action(action)

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Implementation Details

The SO-100 and SO-101 implementations are aliased in the source code: 
# From so_follower.py
SO100Follower = SOFollower
SO101Follower = SOFollower

# From config_so_follower.py
SO100FollowerConfig = SOFollowerRobotConfig
SO101FollowerConfig = SOFollowerRobotConfig
This means all features, bug fixes, and improvements apply to both robots simultaneously.

SO-101

Full documentation for the SO follower series

Robot Overview

See all supported robots

Feetech Motors

Motor bus API documentation

Recording

Collect training data

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