Installation on Windows

Installation on windows:

Installation instructions were copied from here: https://janbernloehr.de/2017/06/10/ros-windows

1. Prerequisite: You need to enable WSL (Windows Subsystem for Linux) for this to work.

2. 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://ha.pool.sks-keyservers.net:80 --recv-key 421C365BD9FF1F717815A3895523BAEEB01FA116
   sudo apt-get update
   sudo apt-get install ros-melodic-desktop-full
   sudo rosdep init
   rosdep update

   If it gives error gpg dirmngr IPC connect call failed then run the following instead:

   sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
   curl -sL "http://keyserver.ubuntu.com/pks/lookup?op=get&search=0x5523BAEEB01FA116" | sudo apt-key add
   sudo apt-get update
   sudo apt-get install ros-melodic-desktop-full
   sudo rosdep init
   rosdep update

3. If you want to source ros lunar automatically for ever bash session, then:

   echo "source /opt/ros/lunar/setup.bash" >> ~/.bashrc
   source ~/.bashrc

4. Install the Ximg X Server after downloading from here: https://sourceforge.net/projects/xming/

5. After you have installed Xming, you also need to configure WSL to use it. To do so modify you .bashrc as follows

   echo "export DISPLAY=:0" >> ~/.bashrc
   source ~/.bashrc

Testing the Installation

1. Start a new bash prompt and run roscore

2. Start a second bash prompt

3. Create a new file publish.py with the contents

   #!/usr/bin/env python
   import rospy
   from std_msgs.msg import String
      
   pub = rospy.Publisher('chatter', String, queue_size=None)
   rospy.init_node('demo_pub_node')
   r = rospy.Rate(1) # 10hz
   while not rospy.is_shutdown():
      pub.publish("hello world")
      print('sending data...')
      r.sleep()

4. Run the publisher python publish.py

5. Start a third bash prompt

6. Create a new file subscribe.py with the contents

   #!/usr/bin/env python
   import rospy
   from std_msgs.msg import String
      
   def callback(data):
       rospy.loginfo("I heard %s",data.data)
      
   def listener():
       rospy.init_node('demo_sub_node')
       rospy.Subscriber("chatter", String, callback)
       # spin() simply keeps python from exiting until this node is stopped
       rospy.spin()
      
   listener()

7. Run the subscriber python subscribe.py

Running all the above steps should give the following output:

Testing the Installation usign Xming

1. Start a new bash prompt and run roscore.

2. Start a second bash prompt and run rosrun turtlesim turtle_teleop_key.

3. Start a third bash prompt and run rosrun turtlesim turtlesim_node. You can control the turtle by using the arrow keys by going back to the second prompt.

Running Multiple instances of shell on the single instance

For this, you need to have tmux installed in your system. A good starting resouce is https://hackernoon.com/a-gentle-introduction-to-tmux-8d784c404340

If you want to delve deeper, here is another: https://leanpub.com/the-tao-of-tmux/read