lerobot/docs/source/openarm.mdx

# OpenArm

[OpenArm](https://openarm.dev) is an open-source 7DOF humanoid arm designed for physical AI research and deployment.

To get your OpenArm, assembled or DIY, and join the global community, browse verified and certified manufacturers worldwide at [openarm.dev](https://openarm.dev).

## What's Unique?

- **Human-Scale Design**: OpenArm is designed with human-like proportions, scaled for a person around 160-165cm tall. This provides an optimal balance between practical reach and manageable inertia for safe, responsive operation.

- **Safety-First Architecture**: Built with QDD backdrivable motors and high compliance, OpenArm prioritizes safe human-robot interaction while maintaining practical payload capabilities (6.0kg peak / 4.1kg nominal) for real-world tasks.

- **Built for Durability**: Critical structural components use aluminum and stainless steel construction, ensuring robust performance for repetitive data collection and continuous research use.

- **Fully Accessible & Buildable**: Every component, from CNC parts and 3D-printed casings to electrical wiring is designed to be purchasable and buildable by individual researchers and labs, with complete fabrication data provided.

- **Practical & Affordable**: At $6,500 USD for a complete bimanual system, OpenArm delivers research-grade capabilities at a fraction of traditional humanoid robot costs.

## Platform Requirements

<Tip warning={true}>
  **Linux Only**: OpenArm currently only works on Linux. The CAN bus USB adapter
  does not have macOS drivers and has not been tested on Windows.
</Tip>

## Safety Guide

Before operating OpenArm, please read the [official safety guide](https://docs.openarm.dev/getting-started/safety-guide). Key points:

- **Secure installation**: Fasten the arm to a flat, stable surface with screws or clamps
- **Safe distance**: Keep body parts and objects outside the range of motion during operation
- **Protective equipment**: Always wear safety goggles; use additional PPE as needed
- **Payload limits**: Do not exceed specified payload limits (6.0kg peak / 4.1kg nominal per arm)
- **Emergency stop**: Know the location and operation of the emergency stop device
- **Regular inspection**: Check for loose screws, damaged mechanical limits, unusual noises, and wiring damage

## Hardware Setup

Follow the official [OpenArm hardware documentation](https://docs.openarm.dev) for:

- Bill of materials and sourcing
- 3D printing instructions
- Mechanical assembly
- Electrical wiring

The hardware repositories are available at [github.com/enactic/openarm](https://github.com/enactic/openarm).

## CAN Bus Setup

OpenArm uses CAN bus communication with Damiao motors. Once you have the CAN bus USB adapter plugged into your Linux PC, follow the [Damiao Motors and CAN Bus guide](./damiao) to configure the interface.

Quick setup:

```bash
# Setup CAN interfaces
lerobot-setup-can --mode=setup --interfaces=can0,can1

# Test motor communication
lerobot-setup-can --mode=test --interfaces=can0,can1
```

## Install LeRobot 🤗

Follow our [Installation Guide](./installation), then install the Damiao motor support:

```bash
pip install -e ".[damiao]"
```

## Usage

### Follower Arm (Robot)

<hfoptions id="follower">
<hfoption id="Command">

```bash
lerobot-calibrate \
    --robot.type=openarm_follower \
    --robot.port=can0 \
    --robot.side=right \
    --robot.id=my_openarm_follower
```

</hfoption>
<hfoption id="API example">

```python
from lerobot.robots.openarm_follower import OpenArmFollower, OpenArmFollowerConfig

config = OpenArmFollowerConfig(
    port="can0",
    side="right",  # or "left" for left arm
    id="my_openarm_follower",
)

follower = OpenArmFollower(config)
follower.connect()

# Read current state
obs = follower.get_observation()
print(obs)

# Send action (position in degrees)
action = {
    "joint_1.pos": 0.0,
    "joint_2.pos": 0.0,
    "joint_3.pos": 0.0,
    "joint_4.pos": 45.0,
    "joint_5.pos": 0.0,
    "joint_6.pos": 0.0,
    "joint_7.pos": 0.0,
    "gripper.pos": 0.0,
}
follower.send_action(action)

follower.disconnect()
```

</hfoption>
</hfoptions>

### Leader Arm (Teleoperator)

The leader arm is used for teleoperation - manually moving it to control the follower arm.

<hfoptions id="leader">
<hfoption id="Command">

```bash
lerobot-calibrate \
    --teleop.type=openarm_leader \
    --teleop.port=can1 \
    --teleop.id=my_openarm_leader
```

</hfoption>
<hfoption id="API example">

```python
from lerobot.teleoperators.openarm_leader import OpenArmLeader, OpenArmLeaderConfig

config = OpenArmLeaderConfig(
    port="can1",
    id="my_openarm_leader",
    manual_control=True,  # Disable torque for manual movement
)

leader = OpenArmLeader(config)
leader.connect()

# Read current position (as action to send to follower)
action = leader.get_action()
print(action)

leader.disconnect()
```

</hfoption>
</hfoptions>

### Teleoperation

To teleoperate OpenArm with leader-follower control:

```bash
lerobot-teleoperate \
    --robot.type=openarm_follower \
    --robot.port=can0 \
    --robot.side=right \
    --robot.id=my_follower \
    --teleop.type=openarm_leader \
    --teleop.port=can1 \
    --teleop.id=my_leader
```

### Bimanual Teleoperation

To teleoperate a bimanual OpenArm setup with two leader and two follower arms:

```bash
lerobot-teleoperate \
    --robot.type=bi_openarm_follower \
    --robot.left_arm_config.port=can0 \
    --robot.left_arm_config.side=left \
    --robot.right_arm_config.port=can1 \
    --robot.right_arm_config.side=right \
    --robot.id=my_bimanual_follower \
    --teleop.type=bi_openarm_leader \
    --teleop.left_arm_config.port=can2 \
    --teleop.right_arm_config.port=can3 \
    --teleop.id=my_bimanual_leader
```

### Recording Data

To record a dataset during teleoperation:

```bash
lerobot-record \
    --robot.type=openarm_follower \
    --robot.port=can0 \
    --robot.side=right \
    --robot.id=my_follower \
    --teleop.type=openarm_leader \
    --teleop.port=can1 \
    --teleop.id=my_leader \
    --repo-id=my_hf_username/my_openarm_dataset \
    --fps=30 \
    --num-episodes=10
```

## Configuration Options

### Follower Configuration

| Parameter             | Default   | Description                                                |
| --------------------- | --------- | ---------------------------------------------------------- |
| `port`                | -         | CAN interface (e.g., `can0`)                               |
| `side`                | `None`    | Arm side: `"left"`, `"right"`, or `None` for custom limits |
| `use_can_fd`          | `True`    | Enable CAN FD for higher data rates                        |
| `can_bitrate`         | `1000000` | Nominal bitrate (1 Mbps)                                   |
| `can_data_bitrate`    | `5000000` | CAN FD data bitrate (5 Mbps)                               |
| `max_relative_target` | `None`    | Safety limit for relative target positions                 |
| `position_kp`         | Per-joint | Position control proportional gains                        |
| `position_kd`         | Per-joint | Position control derivative gains                          |

### Leader Configuration

| Parameter          | Default   | Description                         |
| ------------------ | --------- | ----------------------------------- |
| `port`             | -         | CAN interface (e.g., `can1`)        |
| `manual_control`   | `True`    | Disable torque for manual movement  |
| `use_can_fd`       | `True`    | Enable CAN FD for higher data rates |
| `can_bitrate`      | `1000000` | Nominal bitrate (1 Mbps)            |
| `can_data_bitrate` | `5000000` | CAN FD data bitrate (5 Mbps)        |

## Motor Configuration

OpenArm uses Damiao motors with the following default configuration:

| Joint                       | Motor Type | Send ID | Recv ID |
| --------------------------- | ---------- | ------- | ------- |
| joint_1 (Shoulder pan)      | DM8009     | 0x01    | 0x11    |
| joint_2 (Shoulder lift)     | DM8009     | 0x02    | 0x12    |
| joint_3 (Shoulder rotation) | DM4340     | 0x03    | 0x13    |
| joint_4 (Elbow flex)        | DM4340     | 0x04    | 0x14    |
| joint_5 (Wrist roll)        | DM4310     | 0x05    | 0x15    |
| joint_6 (Wrist pitch)       | DM4310     | 0x06    | 0x16    |
| joint_7 (Wrist rotation)    | DM4310     | 0x07    | 0x17    |
| gripper                     | DM4310     | 0x08    | 0x18    |

## Troubleshooting

### No Response from Motors

1. Check power supply connections
2. Verify CAN wiring (CAN-H, CAN-L, GND)
3. Run diagnostics: `lerobot-setup-can --mode=test --interfaces=can0`
4. See the [Damiao troubleshooting guide](./damiao#troubleshooting) for more details

### CAN Interface Not Found

Ensure the CAN interface is configured:

```bash
ip link show can0
```

## Resources

- [OpenArm Website](https://openarm.dev)
- [OpenArm Documentation](https://docs.openarm.dev)
- [OpenArm GitHub](https://github.com/enactic/openarm)
- [Safety Guide](https://docs.openarm.dev/getting-started/safety-guide)
- [Damiao Motors and CAN Bus](./damiao)