Marty V2 ROS 2

Connect a Marty V2 over USB or Wi-Fi and read its accelerometer in ROS 2. Use Ubuntu 24.04, ROS 2 Jazzy, Python 3.12 and a Bash terminal.

1. Set up and build

Install ROS using the Ubuntu installation instructions, then install the build tools:

sudo apt install ros-dev-tools python3-venv python3-pip
sudo rosdep init  # Once per machine; skip if already initialized.
rosdep update

Clone the repository into any directory, then run from its root:

git clone https://github.com/robotical/marty-ros2.git
cd marty-ros2
source /opt/ros/jazzy/setup.bash
/usr/bin/python3 -m venv --system-site-packages .venv
source .venv/bin/activate
python -m pip install -r requirements.txt colcon-common-extensions
rosdep install --from-paths src --ignore-src -r -y
python "$(command -v colcon)" build --base-paths src --symlink-install

The virtual environment includes the ROS installation's Python packages and MartyPy. Run colcon explicitly through the active Python as shown above: a system colcon executable otherwise builds the driver with system Python, even while the venv is active. The generated driver executable keeps that build-time interpreter.

2. Configure the machine and Marty

Create these local files once; both are ignored by Git:

cp -n config/machine.env.example config/machine.env
cp -n config/robots.yaml.example config/robots.yaml

config/machine.env sets the ROS installation, DDS domain, Python environment and robot file:

ROS_SETUP_FILE=/opt/ros/jazzy/setup.bash
ROS_DOMAIN_ID=0
MARTY_PYTHON_VENV="$MARTY_ROS_ROOT/.venv"
MARTY_ROS_ROBOTS_FILE="$MARTY_ROS_ROOT/config/robots.yaml"

The setup script determines MARTY_ROS_ROOT from its own location. The workspace defaults to that checkout; set ROS_WORKSPACE for a separate build workspace. Relative configuration paths are resolved from the checkout. Use the same ROS_DOMAIN_ID in every ROS terminal.

For USB, edit config/robots.yaml:

martys:
  marty:
    method: usb
    locator: /dev/serial/by-id/REPLACE_WITH_MARTY_DEVICE
    auto_connect: false
    auto_reconnect: false
    subscribe_rate_hz: 10.0

Find the USB path with ls -l /dev/serial/by-id/. If access is denied, run sudo usermod -aG dialout "$USER", then log out and back in.

For Wi-Fi, replace method and locator inside the same entry:

    method: wifi
    locator: 192.168.1.8

Use Marty's actual IP address or hostname, without http:// or ws://. Marty must already be connected to the Wi-Fi network.

Defaults are in src/marty_bringup/config/marty.yaml. Values in robots.yaml override those defaults; explicit launch arguments override both. Additional entries need unique namespaces and connections. Launch each separately with its entry name, for example namespace:=marty2.

3. Connect and read acceleration

Run from the repository root. In Terminal 1:

source scripts/setup_env.sh
ros2 launch marty_bringup bringup.launch.py namespace:=marty

The script loads machine.env, activates the Python environment and sources the built workspace. Launch selects marty from the robot file. Keep this terminal running; Marty stays disconnected until the next command.

In Terminal 2, prepare the environment, connect and display acceleration:

source scripts/setup_env.sh
ros2 service call /marty/connect std_srvs/srv/Trigger '{}'
ros2 topic echo /marty/imu/data_raw --field linear_acceleration --qos-reliability best_effort

The service should return success: true. MartyPy starts telemetry on connection; there is no separate acquisition command. The echo prints x, y and z in m/s², including gravity. Move Marty gently to see the readings change.

Ctrl+C stops the echo. Inspect connection state or the ROS graph with:

ros2 topic echo /marty/status --once --qos-durability transient_local
ros2 node info /marty/marty_driver
ros2 topic list -t

4. Stop

Disconnect in Terminal 2, then Ctrl+C in Terminal 1 stops the driver:

ros2 service call /marty/disconnect std_srvs/srv/Trigger '{}'

Connection starts no movement. Movement commands, topic types, configuration and model integration are described in ROS interfaces. The accelerometer provides acceleration only; gyro and orientation are unavailable. For a separate Marty simulation with joint controls and RViz, see simulation.

The Marty ROS 2 userguide covers setup, telemetry and movement commands. See validation for automated and physical checks. For an onboard Raspberry Pi driver and camera with RViz on another Linux machine, see the Pi setup.