Install procedure

1) go the the home directory and clone the repository by

cd /home/pi/
git clone --recurse-submodules https://github.com/aa4cc/flying-ball-in-hoop.git

Shutdown button service

Copy the service checking whether the shutdown button is pressed to the system directory with other services

sudo cp ~/flying-ball-in-hoop/scripts/pi_shutdown.service /lib/systemd/system/

Enable the service to automatically start when raspberry pi boots

sudo systemctl enable pi_shutdown.service

Run the service so you don not have to reboot the raspberry pi

sudo systemctl start pi_shutdown.service

Now you can check the status of the service by running

sudo systemctl status pi_shutdown.service

Install OpenCV

This guide vaguely follows a guide written here but this one is altered and valid for Raspbian Stretch.

1. Log in and change password.

2. Connect to the Internet.

3. Skip Step #1 in the above-mentioned guide and go to Step #2 - with Raspbian Stretch there is no need to expand the filesystem.

4. Update packages:

    sudo apt-get update
   

5. Upgrade packages:

    sudo apt-get upgrade
   

6. Install CMake:

    sudo apt-get install build-essential cmake pkg-config
   

7. Get image file formats support:

    sudo apt-get install libjpeg-dev libtiff5-dev libjasper-dev libpng12-dev
   

8. Get video file formats support:

    sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev
    sudo apt-get install libxvidcore-dev libx264-dev
   

9. Install GTK development library:

    sudo apt-get install libgtk2.0-dev
   

10. Install other useful dependencies:

    sudo apt-get install libatlas-base-dev gfortran
    

11. Install Python:

    sudo apt-get install python2.7-dev python3-dev
    

12. Get OpenCV archive:

    cd ~ (or cd /home/pi)
    wget -O opencv.zip https://github.com/Itseez/opencv/archive/3.4.3.zip
    unzip opencv.zip
    

13. Install pip:

    sudo apt-get install python3-pip
    

14. Install NumPy:

    pip3 install numpy
    

15. Setup build via CMake:

    cd ~/opencv-3.4.3/
    mkdir build
    cd build
    cmake -D CMAKE_BUILD_TYPE=RELEASE \
       -D CMAKE_INSTALL_PREFIX=/usr/local \
       -D INSTALL_PYTHON_EXAMPLES=ON \
       -D ENABLE_PRECOMPILED_HEADERS=OFF \
       -D BUILD_EXAMPLES=ON ..
    

16. Compile OpenCV:

    make -j4
    

17. Install OpenCV:

    sudo make install
    sudo ldconfig