OK - Here goes - Raspberry PI - older 256Mb version hardware but it works. 8Gb SD card. keyboard, mouse and screen
OS - Raspbain downloaded from http://www.raspberrypi.org/downloads
install the image on the SD card.
plug in the usb hub that the arduino is connect to but do not have the stepper motor driver card attached as this is a test.
Install the SD card into the Raspberry PI hardware - Big point here -> Power ON.
raspi-config screen show up.
login as pi user with the passwd that you setup in above
sudo apt-get install xrdp <remote desktop program>
reboot <to resize the root filesystem so that the rest can be done>
login as pi user
sudo apt-get install arduino <installs pi arduino tool - nice to have>
sudo apt-get install libudev-dev
sudo apt-get install qtcreator
winscp/and scp program the directory and contents for the GrblController software gotten from github <https://github.com/zapmaker/GrblHoming>
into the git directory. I also copied the Hello_World_ShapeOko.nc file into the git directory as a test file.
cd <return to pi home directory>
cd git/G* <move to the build directory for the software>
qmake GcodeSenderGUIthreads.pro <auto configures build environment and files>
make <will build the software>
When the build completes the program GrblController will exist in the build directory.
From your windows box do a remote desktop session to your Raspberry Pi login as pi.
when the gui screen comes up then
select the second from the left icon in the bottom of the screen This is the file browser.
When the file browser starts up it will display the contents of the user pi's home directory.
You will find a folder called git - select it to enter it.
Then select the GrblHoming directory.
Then select the GrblController icon which looks like a gear type of thingee. Should be about 3rd row down and on the far right.
Click on it and It will ask if you want to execute it. select execute.
In the device window select the /dev/ttyACM0 device as this it the port that the Arduino UNO is connected to.
Click the button select file to browse the to the hello_world file and select it.
You should see the default prompt from the arduino/grbl controller in the output command window.
In the command line window above the output command window type in the prompt for your card either a $ or $$ depending as to which version of grbl code is loaded.
the command should be echoed into the command window and also the command output should be displayed.
select the begin button and you will see your output sent to the Grbl controller with X/Y/Z locations changing as it runs.
it works. Runtime for the job was 3 minutes 8 seconds.
Fixed where to get source code.