Rotary Menu Controller

Turning the rotary menu controller one step counterclockwise sends a message to the navigation computer. If the highlighted cursor is not at the top of the list, then the navigation computer should respond by moving the cursor up one position. If the cursor is at the top of the list then there should be no action. If the cursor is on a horizontal list the cursor should move one step left. Turning the rotary menu controller one step clockwise sends a message to the navigation computer. If the highlighted cursor is not at the bottom of the list, then the navigation computer should respond by moving the cursor down one position. If the cursor is at the bottom of the list then there should be no action. If the cursor is on a horizontal list the cursor should move one step right. Pressing and releasing the rotary menu controller sends a message to the navigation computer. The navigation computer should select the currently highlighted menu item or icon and change the display appropriately. If the LCD screen is switched off, pressing and releasing the rotary menu controller will switch the screen on.