Specifications

19
AVR064
2529A–AVR–11/02
After the LCD_displayBuffer has been updated, the LCD_updatedComplete will be set
to FALSE, and LCD_updateRequired to TRUE. This will cause the LCD_displayBuffer to
be written to the LCD in the LCD Start of Frame interrupt.
Scroll Function Figure 16. LCDscrollMsg
This function shifts the six digits on the LCD one step to the left. An external delay or
interrupt is needed in order to get the right speed of the scrolling text. The scroll function
uses a pointer to keep track of what characters to shift in and out of the LCD. When all
the six digits have been updated, the pointer gets incremented by one in order to shift
the text-string one step the next time this function is called.
If the pointer has reached the end of the string, the LCD has to be filled up with one
ASCII-space at the time until all of the six digits are blank. This will “fade” out the text
string.
String
Pointer at
the End of
String?
Write Six
Characters from the
String to the
LCD_displayBuffer
Yes
No
Increment
String Pointer
Add one "Space" and
Write the Remaining
Characters from
String to the
LCD_displayBuffer
No
Yes
If not Set to
Infinite Scrolling,
Decrement the
NumberOfScroll
Variable
LCD
Display
Empty?
Clear
String Counter
Return
LCDscrollMsg