SDK Development =============== This section summarises how to set up and develop applications for the Unitree H2 using the official SDKs. It is based on Unitree's `H2 Developer Guide `_ and the public Unitree repositories. Always treat the official guide as the authoritative reference for your firmware version. Overview -------- The H2 is controlled through Unitree's CycloneDDS-based communication stack, which operates with or without ROS 2 while remaining ROS 2 compatible. Three primary SDKs are available: - **unitree_sdk2** — the C++ SDK for high- and low-level control, state subscription, and sensor access. Repository: `unitree_sdk2 `_. - **unitree_sdk2_python** — the Python interface (pybind11 wrapper) for rapid prototyping. Repository: `unitree_sdk2_python `_. - **unitree_ros2** — ROS 2 packages that bridge the same DDS interface into ROS 2 topics and messages. Repository: `unitree_ros2 `_. All Unitree open-source SDKs are published under the `Unitree Robotics GitHub organisation `_. Requirements ------------ +-------------------------------+----------------------------------------------+ | **Item** | **Requirement** | +===============================+==============================================+ | Operating System | Ubuntu 20.04 LTS | +-------------------------------+----------------------------------------------+ | Compiler | GCC 9.4.0 (C++17) | +-------------------------------+----------------------------------------------+ | Build System | CMake 3.10+ | +-------------------------------+----------------------------------------------+ | Architecture | x86_64 or aarch64 | +-------------------------------+----------------------------------------------+ | Transport | DDS (CycloneDDS) | +-------------------------------+----------------------------------------------+ | Python (optional) | Python 3.8+ | +-------------------------------+----------------------------------------------+ Installing Dependencies ----------------------- Install the build toolchain and required libraries: .. code-block:: bash sudo apt update sudo apt install -y cmake g++ build-essential \ libyaml-cpp-dev libeigen3-dev libboost-all-dev \ libspdlog-dev libfmt-dev Building and Installing unitree_sdk2 ------------------------------------ Clone and build the C++ SDK: .. code-block:: bash git clone https://github.com/unitreerobotics/unitree_sdk2.git cd unitree_sdk2 mkdir build && cd build cmake .. make To install the SDK system-wide (recommended for use in your own CMake projects): .. code-block:: bash cd unitree_sdk2/build cmake .. -DCMAKE_INSTALL_PREFIX=/opt/unitree_robotics sudo make install Installing the Python Interface ------------------------------- For Python development, install ``unitree_sdk2_python``: .. code-block:: bash git clone https://github.com/unitreerobotics/unitree_sdk2_python.git cd unitree_sdk2_python pip3 install -e . Network Configuration --------------------- The H2 communicates with a development PC over Gigabit Ethernet using CycloneDDS. Connect the robot and your computer with an Ethernet cable, then identify the interface that links to the robot: .. code-block:: bash # List network interfaces and find the one connected to the H2 ifconfig Unitree robots use the ``192.168.123.x`` subnet by convention. Ensure your development machine is on the **same subnet** as the robot's onboard computer. Configure your PC's wired interface to a static address on that subnet: .. code-block:: bash # Example: set a static IP on the wired interface (replace eth0 with your NIC) sudo ip addr add 192.168.123.222/24 dev eth0 sudo ip link set eth0 up # Confirm the robot is reachable (use the robot's documented address) ping 192.168.123. .. important:: The exact network setup and any robot-specific addresses are documented in the official `H2 Developer Guide `_. Confirm the values for your unit before configuring your PC. Specifying the Network Interface -------------------------------- ``unitree_sdk2`` examples and applications must be told which network interface is connected to the robot. The interface name (for example ``eth0``) is passed as a command-line argument when launching an example: .. code-block:: bash # Run a built example, passing the network interface name ./example_program eth0 In C++, the interface is supplied when initialising the DDS channel factory: .. code-block:: cpp #include int main(int argc, char** argv) { // argv[1] is the network interface connected to the H2 (e.g. "eth0") unitree::robot::ChannelFactory::Instance()->Init(0, argv[1]); // ... create publishers / subscribers and control the robot ... return 0; } The equivalent in Python: .. code-block:: python import sys from unitree_sdk2py.core.channel import ChannelFactoryInitialize # sys.argv[1] is the network interface connected to the H2 (e.g. "eth0") ChannelFactoryInitialize(0, sys.argv[1]) # ... create publishers / subscribers and control the robot ... Control Interfaces ------------------ The SDK exposes both **high-level** and **low-level** control: - **High-level** control issues task-space commands (locomotion modes, posture, velocity) and is the safe default for most applications. - **Low-level** control commands individual joint targets (position, velocity, torque, stiffness, and damping). Low-level commands bypass built-in balancing safeguards and must remain within the documented joint limits. The H2 joint indices, names, and motion limits used by the low-level interface are defined in the SDK headers and the official `H2 Developer Guide `_. Always validate commanded joint motions against the documented limits before sending them. .. warning:: Custom low-level control code can command the robot into unsafe states. Test new control software with the H2 safely supported or in a clear, open area, keep the emergency stop within reach, and validate joint commands against the documented limits before deployment. Further Resources ----------------- - `H2 Developer Guide (official) `_ - `unitree_sdk2 (C++ SDK) `_ - `unitree_sdk2_python (Python interface) `_ - `unitree_ros2 (ROS 2 packages) `_ - `Unitree Robotics on GitHub `_ - `Unitree Document Center `_