SO-100

Compact robotic arm in the SO follower series

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.

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.

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

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.

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
    })

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
)

Motor Configuration

Identical to SO-101:

Motor Name	ID	Model	Range
shoulder_pan	1	STS3215	Full rotation
shoulder_lift	2	STS3215	Limited
elbow_flex	3	STS3215	Limited
wrist_flex	4	STS3215	Limited
wrist_roll	5	STS3215	Full rotation
gripper	6	STS3215	0-100%

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).

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

4. Install LeRobot:

pip install lerobot

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.

Safety Features

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

Relative Target Limiting

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

Torque Management

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

API Reference

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

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

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)

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.

Related Documentation

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