ROS Driver

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Dependencies

Hardware

• A pressure control system running my Ctrl-P firmware
• A desktop computer running Linux (currently tested only in Ubuntu 18.04)

Software

• ROS Melodic
• The rqt_multiplot package for nice plot layouts and custom axes
• Cython HID Library from Trezor:
• The Python Control Interface package for this project
• Various python libraries:
  • All python dependencies are managed in the requirements file. pip install -r requirements.txt

Installation

Install things in this order to ensure everything works:

1. Clone the Python Control Interface package to the src folder of your catkin workspace.
   • Go into the folder and switch to the devel-ros branch

      cd pressure_control_interface
      git checkout devel-ros
     

2. Clone this package to the src folder of your catkin workspace.
3. Install cython-hid dependencies (as specified in the Cython HID Library)

    sudo apt-get install python-dev libusb-1.0-0-dev libudev-dev
    sudo pip install --upgrade setuptools
   

4. Install rqt_multiplot (instructions selected from documentation)

    sudo apt-get install ros-melodic-rqt
    sudo apt-get install libqwt-dev
    sudo apt-get update
    sudo apt-get install ros-melodic-rqt-multiplot
   

5. In the root folder of this package, run pip install -r requirements.txt to install python dependencies for this package and the “pressure_control_interface” package.
6. In the root folder of your catkin workspace, run catkin_make to enable the custom python modules in this package to work.
7. Add the teensy udev rules to enable communication with the pressure controller.
   1. Download the udev rule file. Be sure to save it as “00-teensy.rules”
   2. Open a terminal in the Downloads folder and run sudo cp 00-teensy.rules /etc/udev/rules.d/ to copy the file to the correct location.
   3. Log out of Ubuntu and log back in.

Usage

This driver is split into two ROS packages:

• pressure_trajectory_ros is where trajectories are set up, built, and stored for execution
• pressure_control_ros is the main driver that actually interfaces with the pressure control hardware

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Table of contents

• ROS Basics
• Hardware Setup
• Control Setup
• Basic Tutorial
• Realtime Control

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