Along with the conditional defines parameters, some constants are defined by the unit:
Name / Value |
Used as parameter of |
Comments |
LCD_Width |
Nb of characters in width, according to the conditional compilation symbols. |
|
CURSOR_MOVE_LEFT = $00; |
LCD_CursorMoveMode |
Cursor or text will move to the left at each character write. |
CURSOR_MOVE_RIGHT = $02; |
Cursor or text will move to the right at each character write (default). |
|
CURSOR_MOVE_TEXT = $01; |
Text scrolling: the cursor is fixed and the text scrolls. |
|
DISPLAY_TEXT_ON = $04; |
LCD_DisplayMode |
Show the text (default). |
DISPLAY_TEXT_OFF = $00; |
Hide the text. |
|
DISPLAY_CURSOR_ON = $02; |
Show the cursor. |
|
DISPLAY_CURSOR_OFF = $00; |
Hide the cursor (default). |
|
DISPLAY_CURSOR_FIXED = $00; |
Fixed cursor. |
|
DISPLAY_CURSOR_BLINK = $01; |
Blinking cursor (default). |
|
SHIFT_TEXT = $08; |
LCD_ShiftMode |
Fixed cursor, text is scrolling |
SHIFT_LEFT = $04; |
Shift to the left |
|
SHIFT_RIGHT = $00; |
Shift to the right (default) |
Some constants have been fixed for an HITACHI HD44780U display and may have to be adjusted for slower displays:
Name / Value |
Comments |
LCD_WAIT_DELAY_HOME = 1520; |
In microseconds, for HOME / CLEAR operation: used only if LCD_READ is not defined (no handshake) |
LCD_WAIT_DELAY_NORMAL = 37; |
In microseconds, for other operations: used only if LCD_READ is not defined (no handshake) |
LCD_DATA_DELAY = 2; |
In microseconds, delay after data set before write or read enable pulse |
LCD_ENABLE_DELAY = 5; |
In microseconds, width of the enable pulse to the LCD |
Note: These timing values are now modifiable through conditional defines.