The following was done on a fresh install of Raspberry Pi OS
sudo apt update && sudo apt upgrade
Access sudo raspi-config and go to advanced options and expand the filesystem to allow the entirety of the boot drive to be used. (requires reboot to take effect).
Then setup VNC https://www.raspberrypi.org/documentation/remote-access/vnc/
Open sudo raspi-config, navigate to interfacing options->VNC and enable it.
Then, must specify a resolution that is not the default resolution under Display->resolution.
We also don't want to run the desktop on the pi all the time, so access sudo raspi-config and go to Boot options and choose to run in Console mode (and require user to login)
Open sudo raspi-config again and navigate to System options and set the host name to group5 (meaning the pi will be accessible at group5.local) and the password to groupfive
To start a virtual desktop on the pi, SSH into it and run vncserver.
Note down the IP and dislpay number printed to the terminal and use the RealVNC viewer to connect to this IP.
To end the virtual desktop, run vncserver -kill :<display_number>
#Using http://wiki.ros.org/action/fullsearch/ROSberryPi/Installing%20ROS%20Melodic%20on%20the%20Raspberry%20Pi?action=fullsearch&context=180&value=linkto%3A%22ROSberryPi%2FInstalling+ROS+Melodic+on+the+Raspberry+Pi%22
sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'
#The second command did not work (to add keyserver) so did some research and found this
#(https://discourse.ros.org/t/new-gpg-keys-deployed-for-packages-ros-org/9454) which suggested
sudo apt-key adv --keyserver 'hkp://keyserver.ubuntu.com:80' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654
sudo apt-get update
sudo apt-get upgrade
sudo apt install -y python-rosdep python-rosinstall-generator python-wstool python-rosinstall build-essential cmake
sudo rosdep init
rosdep update
mkdir -p ~/ros_catkin_ws
cd ~/ros_catkin_ws
rosinstall_generator ros_comm --rosdistro melodic --deps --wet-only --tar > melodic-ros_comm-wet.rosinstall
wstool init src melodic-ros_comm-wet.rosinstall
cd ~/ros_catkin_ws
rosdep install -y --from-paths src --ignore-src --rosdistro melodic -r --os=debian:buster
#before doing make expand swapfile size (as I found the CMAKE command below failed without doing so)
#open the file in /etc/dphys-swapfile (you will need root permissions to modify) and change CONF_SWAPSIZE to
#CONF_SWAPSIZE=1024. then reboot to make sure changes take effect
sudo reboot now
cd ~/ros_catkin_ws
sudo ./src/catkin/bin/catkin_make_isolated --install -DCMAKE_BUILD_TYPE=Release --install-space /opt/ros/melodic -j2
source /opt/ros/melodic/setup.bash
echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
sudo apt-get install python-catkin-tools
mkdir -p ~/catkin_ws/src
cd ~/catkin_ws
source /opt/ros/melodic/setup.bash
catkin build
echo "source ~/catkin_ws/devel/setup.bash" >> ~/.bashrc
Install opencv: sudo apt install python-opencv (get python2 compatible version to work with ROS melodic and python 2 compatability)
Get pigpio daemon to run on startup with: sudo systemctl enable pigpiod. Will require reboot to take effect or also run sudo systemctl start pigpiod to start immediately