> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/huggingface/lerobot/llms.txt
> Use this file to discover all available pages before exploring further.

# lerobot-setup-can

> Configure and test CAN interfaces for Damiao motors

The `lerobot-setup-can` command helps setup and debug CAN (Controller Area Network) interfaces for Damiao motors used in robots like OpenArms.

## Command

```bash theme={null}
lerobot-setup-can [OPTIONS]
```

Location: `src/lerobot/scripts/lerobot_setup_can.py`

## Overview

This utility:

* Configures CAN interfaces with CAN FD support
* Tests motor connectivity on CAN bus
* Performs speed and latency benchmarks
* Supports multiple CAN interfaces (can0, can1, can2, can3)
* Validates Damiao motor communication

## Key Options

<ParamField path="--mode" type="str" default="test">
  Operation mode: `setup`, `test`, or `speed`.
</ParamField>

<ParamField path="--interfaces" type="str" default="can0">
  Comma-separated CAN interface names (e.g., `"can0,can1,can2,can3"`).
</ParamField>

<ParamField path="--bitrate" type="int" default="1000000">
  CAN bitrate in bits/second (1 Mbps default).
</ParamField>

<ParamField path="--data_bitrate" type="int" default="5000000">
  CAN FD data bitrate in bits/second (5 Mbps default).
</ParamField>

<ParamField path="--use_fd" type="bool" default="true">
  Enable CAN FD (Flexible Data-rate).
</ParamField>

<ParamField path="--motor_ids" type="list[int]" default="[1,2,3,4,5,6,7,8]">
  Motor IDs to test (0x01-0x08).
</ParamField>

<ParamField path="--timeout" type="float" default="1.0">
  Motor response timeout in seconds.
</ParamField>

<ParamField path="--speed_iterations" type="int" default="100">
  Number of iterations for speed test.
</ParamField>

## Usage Examples

### Setup CAN Interfaces

Configure CAN interfaces with CAN FD:

```bash theme={null}
lerobot-setup-can --mode=setup --interfaces=can0,can1,can2,can3
```

This:

* Sets bitrate to 1 Mbps
* Sets data bitrate to 5 Mbps (CAN FD)
* Brings up all specified interfaces
* Requires sudo permissions

### Test Motors on Single Interface

```bash theme={null}
lerobot-setup-can --mode=test --interfaces=can0
```

Tests motors 0x01-0x08 on can0 and reports:

* Which motors respond
* Response data from each motor
* Summary of found motors

### Test Motors on All Interfaces

```bash theme={null}
lerobot-setup-can --mode=test --interfaces=can0,can1,can2,can3
```

Tests all four CAN interfaces and shows motors on each bus.

### Speed Test

Benchmark communication speed:

```bash theme={null}
lerobot-setup-can --mode=speed --interfaces=can0 --speed_iterations=100
```

Reports:

* Average latency (ms)
* Success rate
* Maximum achievable frequency (Hz)

### Custom Configuration

```bash theme={null}
lerobot-setup-can \
  --mode=setup \
  --interfaces=can0,can1 \
  --bitrate=500000 \
  --data_bitrate=2000000 \
  --use_fd=true
```

## Mode Details

### Setup Mode

Configures CAN interfaces:

```bash theme={null}
lerobot-setup-can --mode=setup --interfaces=can0
```

Executes:

1. Brings down interface: `sudo ip link set can0 down`
2. Configures CAN: `sudo ip link set can0 type can bitrate 1000000 dbitrate 5000000 fd on`
3. Brings up interface: `sudo ip link set can0 up`

Output:

```text theme={null}
==================================================
CAN Interface Setup
==================================================
Mode: CAN FD
Bitrate: 1.0 Mbps
Data bitrate: 5.0 Mbps

Configuring can0...
  ✓ can0: UP (CAN FD)

Setup complete!

Next: Test motors with:
  lerobot-setup-can --mode=test --interfaces can0
```

### Test Mode

Tests motor connectivity:

```bash theme={null}
lerobot-setup-can --mode=test --interfaces=can0
```

For each motor:

1. Sends enable command (0xFC)
2. Waits for response
3. Sends disable command (0xFD)
4. Reports findings

Output:

```text theme={null}
==================================================
CAN Motor Test
==================================================
Testing motors 0x01-0x08
Mode: CAN FD

can0: UP (CAN FD)
  Motor 0x01 (joint_1): ✓ FOUND
    → Response 0x01 [FD]: ffffffffffff7ffc
  Motor 0x02 (joint_2): ✓ FOUND
    → Response 0x02 [FD]: ffffffffffff7ffc
  Motor 0x03 (joint_3): ✗ No response
  Motor 0x04 (joint_4): ✗ No response
  Motor 0x05 (joint_5): ✓ FOUND
    → Response 0x05 [FD]: ffffffffffff7ffc
  Motor 0x06 (joint_6): ✓ FOUND
    → Response 0x06 [FD]: ffffffffffff7ffc
  Motor 0x07 (joint_7): ✗ No response
  Motor 0x08 (gripper): ✓ FOUND
    → Response 0x08 [FD]: ffffffffffff7ffc

  Summary: 5/8 motors found

==================================================
Summary
==================================================
Total motors found: 5
```

### Speed Mode

Benchmarks communication performance:

```bash theme={null}
lerobot-setup-can --mode=speed --interfaces=can0
```

Output:

```text theme={null}
==================================================
CAN Speed Test
==================================================

can0: Running speed test (100 iterations)...
  Testing with motor 0x01...
  ✓ Success rate: 100/100
  ✓ Avg latency: 1.23 ms
  ✓ Max frequency: 813.0 Hz
```

## Motor Mapping

Default motor ID to joint mapping:

| ID   | Joint Name |
| ---- | ---------- |
| 0x01 | joint\_1   |
| 0x02 | joint\_2   |
| 0x03 | joint\_3   |
| 0x04 | joint\_4   |
| 0x05 | joint\_5   |
| 0x06 | joint\_6   |
| 0x07 | joint\_7   |
| 0x08 | gripper    |

## Troubleshooting

### Interface Not Found

**Output:**

```text theme={null}
can0: Interface not found - skipping
```

**Causes:**

* CAN hardware not connected
* Wrong interface name
* Driver not loaded

**Solutions:**

```bash theme={null}
# List available network interfaces
ip link show

# Check for CAN interfaces
ls /sys/class/net/ | grep can

# Load CAN drivers (if needed)
sudo modprobe can
sudo modprobe can_raw
sudo modprobe vcan  # Virtual CAN for testing
```

### Permission Denied

**Error:**

```text theme={null}
Failed to configure: Permission denied
```

**Solution:**
Run with sudo or configure sudo access:

```bash theme={null}
# Option 1: Run with sudo
sudo lerobot-setup-can --mode=setup --interfaces=can0

# Option 2: Add user to netdev group (then log out/in)
sudo usermod -a -G netdev $USER
```

### No Motors Found

**Output:**

```text theme={null}
Total motors found: 0

⚠ No motors found! Check:
  1. Motors are powered (24V)
  2. CAN wiring (CANH, CANL, GND)
  3. Motor timeout parameter > 0 (use Damiao tools)
  4. 120Ω termination at both cable ends
  5. Interface configured: lerobot-setup-can --mode=setup --interfaces can0
```

**Solutions:**

1. **Check Power**: Ensure motors have 24V power
2. **Check Wiring**:
   * CANH connected to CANH
   * CANL connected to CANL
   * GND connected
3. **Check Termination**: 120Ω resistors at both cable ends
4. **Check Motor Configuration**: Use Damiao software to verify:
   * Motor IDs are correct (0x01-0x08)
   * Timeout parameter > 0
   * Motors are in correct mode
5. **Test Interface**:
   ```bash theme={null}
   # Verify interface is UP
   ip link show can0

   # Should show: "can0: <NOARP,UP,LOWER_UP,ECHO> ... state UP"
   ```

### Connection Timeouts

**Cause:**
CAN interface configuration or hardware issues.

**Solutions:**

```bash theme={null}
# Restart interface
sudo ip link set can0 down
sudo ip link set can0 up

# Reconfigure
lerobot-setup-can --mode=setup --interfaces=can0

# Test with lower bitrate
lerobot-setup-can \
  --mode=setup \
  --interfaces=can0 \
  --bitrate=500000 \
  --data_bitrate=2000000
```

### Slow Communication

**Speed test shows low frequency:**

```text theme={null}
✓ Max frequency: 150.0 Hz  # Should be > 500 Hz
```

**Solutions:**

* Use CAN FD: `--use_fd=true`
* Increase data bitrate: `--data_bitrate=5000000`
* Check cable quality (use short, high-quality cables)
* Reduce number of motors per bus
* Check CPU load during operation

## Hardware Setup

### CAN Bus Wiring

```text theme={null}
[Controller]     [Motor 1]     [Motor 2]     [Motor N]
   |               |             |             |
  CANH ---------- CANH -------- CANH -------- CANH
  CANL ---------- CANL -------- CANL -------- CANL
   GND ---------- GND --------- GND --------- GND
   |                                           |
  120Ω                                         120Ω
```

### Termination Resistors

* Place 120Ω resistors at both ends of the CAN bus
* Required for signal integrity
* Without termination: reflections cause errors

### Cable Recommendations

* Use twisted pair cable (CANH/CANL)
* Keep cables short (under 5 meters ideal)
* Use shielded cable in noisy environments
* Connect shield to GND at one end only

## Advanced Usage

### Test Specific Motors

```bash theme={null}
lerobot-setup-can \
  --mode=test \
  --interfaces=can0 \
  --motor_ids="[1, 2, 5, 8]"
```

Tests only motors 0x01, 0x02, 0x05, 0x08.

### Extended Speed Test

```bash theme={null}
lerobot-setup-can \
  --mode=speed \
  --interfaces=can0 \
  --speed_iterations=1000
```

Runs 1000 iterations for more accurate benchmarking.

### Disable CAN FD

For compatibility with older devices:

```bash theme={null}
lerobot-setup-can \
  --mode=setup \
  --interfaces=can0 \
  --use_fd=false \
  --bitrate=1000000
```

## See Also

* [OpenArm Documentation](https://github.com/TheRobotStudio/OpenArm)
* [Damiao Motor Documentation](http://www.dmke-robot.com/)
* [Linux SocketCAN](https://www.kernel.org/doc/html/latest/networking/can.html)
* [Robot API](/api/robot) - Robot control interface