If you use 4 workspaces as default in Ubuntu (and I suspect that this is your case because you said rotate the workspaces), you can use the following script:

#!/bin/bash



#check if xdotool is installed

if [ ! -n "$(dpkg -s xdotool 2>/dev/null | grep 'Status: install ok installed')" ]; then

    echo -e "The package 'xdotool' must to be installed before to run $(basename $0)

Use 'sudo apt-get install xdotool' command in terminal to install it."

    exit

fi



delay=5 #change as you wish



echo "Press Ctrl+C to finish"



#start with workspace 0 (top left)

xdotool key Ctrl+Alt+Left

xdotool key Ctrl+Alt+Up



#switch workspaces 

while : ; do

    workspace_nr=0

    until [ $workspace_nr = 4 ]; do

        sleep $delay

        case $workspace_nr in 

            0) xdotool key Ctrl+Alt+Right ;;

            1) xdotool key Ctrl+Alt+Down ;;

            2) xdotool key Ctrl+Alt+Left ;;

            3) xdotool key Ctrl+Alt+Up ;;

        esac

        ((workspace_nr++))

    done

done