TaShan Sensor Setup with Python 3.8

TaShan touch sensors require Python 3.8 due to their dependency on libpython3.8.so.1.0. This guide explains how to set up Python 3.8 with ROS support using Conda and RoboStack.

The Challenge

Using Python 3.8 with ROS on modern systems can be challenging since most ROS distributions are built for newer Python versions.

Solution: Conda with RoboStack

Prerequisites

• Conda or Miniconda installed

• TaShan sensor library files in dexrobot_mujoco/ts_sensor_lib/

Setup Steps

1. Create Python 3.8 Environment with ROS

   conda create -n tashan_env python=3.8
   conda activate tashan_env
   
   # Add RoboStack channel
   conda config --add channels conda-forge
   conda config --add channels robostack
   
   # Install ROS Foxy base
   conda install ros-foxy-ros-base
   

2. Install Required Dependencies

   # Install specific spdlog version
   conda install spdlog=1.8.2
   
   # Upgrade numpy via pip
   pip install --upgrade numpy
   
   # Install MuJoCo 3.2.3
   pip install mujoco==3.2.3
   
   # Install dexrobot_mujoco with TaShan support
   cd /path/to/dexrobot_mujoco
   pip install -e .[tashan]
   

3. Configure Environment Variables

   # Ensure LD_LIBRARY_PATH includes conda libraries
   export LD_LIBRARY_PATH=$CONDA_PREFIX/lib:$LD_LIBRARY_PATH
   
   # Set RMW implementation
   export RMW_IMPLEMENTATION=rmw_cyclonedds_cpp
   
   # Source ROS setup
   source $CONDA_PREFIX/setup.bash
   

4. Verify Installation

   # Check Python version
   python --version  # Should show Python 3.8.x
   
   # Check MuJoCo version
   python -c "import mujoco; print(mujoco.__version__)"  # Should show 3.2.3
   
   # Check ROS
   ros2 topic list  # Should work without errors
   

Running with TaShan Sensors

With ROS support:

python nodes/dexrobot_mujoco_ros.py dexrobot_mujoco/scenes/box.xml \
    --config config/scene_default.yaml \
    --enable-ts-sensor

Standalone (without ROS):

python examples/tashan_standalone_demo.py

Troubleshooting

Library not found errors:

• Ensure LD_LIBRARY_PATH includes $CONDA_PREFIX/lib

• Check that TaShan .so files are in dexrobot_mujoco/ts_sensor_lib/linux/

ROS communication issues:

• Verify RMW_IMPLEMENTATION is set correctly

• Check that all ROS nodes are using the same RMW implementation

Import errors:

• Make sure you’re in the correct conda environment

• Reinstall packages in the correct order if needed

Alternative: Standalone Usage

If ROS integration proves too complex, you can use TaShan sensors without ROS. See examples/tashan_standalone_demo.py for a minimal example that demonstrates TaShan sensor functionality without ROS dependencies.