User manual
ECE 477 Final Report Spring 2004
memory. Simultaneously, the LCD screen will be set to show “Updating… Please Wait” until
the process is over, when it will resume normal function by displaying the main menu and going
back to sleep.
Button Interrupt
The button interrupt indicates that someone is moving through the menu structure.
Pressing the “up” arrow will cause the current item to be deselected and the item above it In the
list to be highlighted, if such an item exists. The down arrow will do the same thing, only in
reverse. “Highlighted” means that the pixels are to be XOR’ed, and the text is blank while the
background is liquid crystal. A press of the right arrow key will cause the entry for the current
line in the function map to be accessed. If it is text, nothing will happen. If it is a sub-menu
item, the new menu will be called and displayed. If it an item, it will send the order and return to
the main menu. A press of the left arrow button will return to the main menu (a sort of
“cancel”).
LCD Functions
Because of the complexity of access to the LCD unit, several general functions are being
written.
• LCD_print() - Takes in 2 arguments, the memory location of the line and the line number
to be displayed.
• LCD_invert() – Takes in 1 argument, the line to be inverted.
• LCD_write() – Takes in the memory location and the character to write to it.
Several more functions may get written as the software is being developed, as their usefulness
become apparent.
Software Design Narrative – Base Computer
Much has been said about the embedded application code, but it is not the only software
that needs to be written. Another program has been written for the base computer that will
receive and interpret orders, and send new menus to the mobile device. The program was written
in Visual Basic and was not entirely complicated to make, so not much will be said about its
-35-