Hummingbot

Hummingdrone Nvidia Jetbot integration

Getting Started

Installing

Install Gazebo Model

cp -r ./Gazebo/Model/hummingbot ~/.gazebo/models

Install Gazebo Plugins

mkdir ~/catkin_ws/src/hummingbot_plugin/
cp -r ./Gazebo/Plugins/* ~/catkin_ws/src/hummingbot_plugin/ -rf

Install ROS Packages

cp -r ./ROS/hummingbot/ ~/catkin_ws/src/

Build Your Packages and Plugins

cd ~/catkin_ws/ && catkin_make

Install Joystick

• Install joy package.

sudo apt-get install ros-melodic-joy

• Configure your joystick to your computer.

ls /dev/input

• You should see all input devices here. Joysticks are referred to by jsX. Our case it is js1.

• Test your joystick with command below.

sudo jstest /dev/input/js1

• Move your joystick and see the data changes.

• Make your joystick accessible for ROS node with command below.

sudo chmod a+rw /dev/input/js1

Check out the Model

• Open terminal

roslaunch gazebo_ros empty_world.launch 

• Insert model from the Insert Tab

Playing

• WARNING: If your joystick reference is different than 'js1':

  • Please find the command below in simulation.launch file and change the value with yours.

    <param name="dev" type="string" value="/dev/input/js1" /> 

• Export your build directory

export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:~/catkin_ws/src/hummingbot_plugin/build

• HINT : In order to run your plugins you should run the command above in every terminal session. But there is an easy way as always! If you do not want to write it every time then you can add it into your .bashrc file with the commands below.

  echo "export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:~/catkin_ws/src/hummingbot_plugin/build" >> ~/.bashrc
  source ~/.bashrc

• Finally, run and control your hummingbot!

roslaunch hummingbot simulation.launch

Testing

• Testing Stop Service

rostest hummingbot hummingbot.test

You should see the output below. That means all tests passed and succeed.

SUMMARY
 * RESULT: SUCCESS
 * TESTS: 3
 * ERRORS: 0
 * FAILURES: 0

In this case there are 3 test types for the velocities of any wheel.

• greater or equal
• less or equal
• equal to zero (when stop service is called it should be zero)

Important: No need to check the type of variable. ROS does not allow to any topic that publishes a variable different than its type.

Now joy message includes stop button too. If you remove stop button from the message, test_stop_service method should be failed. That also shows our stop service is working!

Lets remove it and try again!

cd ROS/hummingbot/scripts/test/

Find here publisher.py file and BUTTON_MSG constant inside of the file.

Stop button of joystick is represented as BUTTON_MSG[3].

• If you make that value zero, means no call for stop service.
• If you make that value one, means there is a call for stop service.

So change it as zero, and call test file again. You should see the output below.

SUMMARY
 * RESULT: FAIL
 * TESTS: 3
 * ERRORS: 0
 * FAILURES: 1

Remote ROS Connection

Here explains how to start and control ROS system using multiple machines. ROS_MASTER_URI let you configure multiple machines to use a single ROS master.

Lets think;

• First machine's IP address : 192.168.1.1

• Second machine's IP address: 192.168.1.2

First runs motor and control. Second runs joystick.

• Export IP addresses for both of them.

export ROS_IP="Machine's own IP ADDRESS"

• For SECOND machine:

export ROS_MASTER_URI=http://192.168.1.1:11311 
# exports the ros master's port of first machine

• For FIRST machine:

roslaunch hummingbot robot.launch

• For SECOND machine:

roslaunch hummingbot remote.launch

Now you should control your hummingbot by using remote machine!