Jetbot ROS

Linux Version

Use:jetson-nx-jp451-sd-card-image

Note: the process below will likely exceed the disk capacity of a 16GB filesystem,so a larger SD card should be used(advice more than 64GB).

Install ROS

Install ROS melodic

# enable all Ubuntu packages:
$ sudo apt-add-repository universe
$ sudo apt-add-repository multiverse
$ sudo apt-add-repository restricted

# add ROS repository to apt sources
$ sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
$ sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654

# install ROS Base
$ sudo apt-get update
$ sudo apt-get install ros-melodic-ros-base

# add ROS paths to environment
$ sudo sh -c 'echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc'

Close and restart the terminal.

Install python and adafruit libraries

# pip should be installed
$ sudo apt-get install python-pip

# install Adafruit libraries
$ pip install Adafruit-MotorHAT
$ pip install Adafruit-SSD1306

Add i2c too user

$ sudo usermod -aG i2c $USER

Create the catkin workspace

Create a ROS Catkin workspace to contain our ROS packages.

# create the catkin workspace
$ mkdir -p ~/workspace/catkin_ws/src
$ cd ~/workspace/catkin_ws
$ catkin_make

# add catkin_ws path to bashrc
$ sudo sh -c 'echo "source ~/workspace/catkin_ws/devel/setup.bash" >> ~/.bashrc'

Close and open a new terminal window. Verify that your catkin_ws is visible to ROS.

$ echo $ROS_PACKAGE_PATH 
/home/nvidia/workspace/catkin_ws/src:/opt/ros/melodic/share

Install Jetbot_ros

Clone and build the jetbot_ros repo.

# git and cmake should be installed
$ sudo apt-get install git cmake

# clone the repo
$ cd ~/workspace/catkin_ws/src
$ git clone https://github.com/waveshare/jetbot_ros

# build the package
$ cd ../    # cd ~/workspace/catkin_ws
$ catkin_make

# confirm that jetbot_ros package can be found
$ rospack find jetbot_ros
/home/nvidia/workspace/catkin_ws/src/jetbot_ros

Test Jetbot

Running the ROS master

Next, let's check that the different components of the robot are working under ROS.

First open a new terminal, and start roscore

$ roscore

Roscore

Running the Motors

Open a new terminal, and start the jetbot_motors node.

$ rosrun jetbot_ros jetbot_motors.py

Open a new terminal, and check jetbot_motors node is open.

$ rosnode list
$ rostopic list

Rosnode list

Using the Debug OLED

If you have an SSD1306 debug OLED on your JetBot, you can run the jetbot_oled node to display system information and user-defined text.

$ rosrun jetbot_ros jetbot_oled.py

By default, jetbot_oled will refresh the display every second with the latest memory usage, disk space, and IP addresses.

Ros oled

Use the keyboard to control jetbot movement

Open a new terminal to run teleop_key node.After the program is running, input W, S, D, A four keys on the keyboard to control the jetbot to move forward, backward, right, and left.

$ rosrun jetbot_ros teleop_key.py

You can see the running action from the jetbot_motors node terminal.

Motors node