LCDwrite
Syntax
LCDwrite Ypos, Xpos, [ Value ,{ Value etc…} ]
Overview
Write a byte to a graphic LCD.
Parameters
Ypos :-
With a KS0108 graphic LCD this may be a constant, variable or expression within the range of 0 to 7 This corresponds to the line number of the LCD, with 0 being the top row.
With a Toshiba T6963 graphic LCD this may be a constant, variable or expression within the range of 0 to the Y resolution of the display. With 0 being the top line.
Xpos: -
With a KS0108 graphic LCD this may be a constant, variable or expression with a value of 0 to 127. This corresponds to the X position of the LCD, with 0 being the far left column. With a Toshiba graphic LCD this may be a constant, variable or expression with a value of 0 to the X resolution of the display divided by the font width (LCD_X_Res / LCD_Font_Width). This corresponds to the X position of the LCD, with 0 being the far left column. Value may be a constant, variable, or expression, within the range of 0 to 255 (byte).
Example 1
' Display a line on the top row of a KS0108 graphic LCD
Device = 16F1829
Declare LCD_Type = KS0108
' Target a KS0108 graphic LCD
Dim Xpos as Byte
Cls
' Clear the LCD
For Xpos = 0 to 127
' Create a loop of 128
LCDwrite 0, Xpos, [0b11111111]
' Write to the LCD's top line
DelayMs 100
Next
StopExample 2
' Display a line on the top row of a Toshiba 128x64 graphic LCD
Device = 16F1829
Declare LCD_Type = Toshiba
' Target a Toshiba graphic LCD
Dim Xpos as Byte
Cls
' Clear the LCD
For Xpos = 0 to 20
' Create a loop of 21
LCDwrite 0, Xpos, [0b00111111]
' Write to the LCD's top line
DelayMs 100
Next
StopNotes
The graphic LCDs that are compatible with compiler’s built-in library routines are the KS0108, and the Toshiba T6963. The KS0108 display has a pixel resolution of 64 x 128. The 64 being the Y axis, made up of 8 lines each having 8-bits. The 128 being the X axis, made up of 128 positions. The Toshiba LCDs are available with differing resolutions. Xpos 0 - 127 lsb Line 0 msb
Line 1 Ypos 0 - 63
Line 2
Samsung KS0108 graphic LCD
Xpos 0 - n msb lsb
Line 0
Line 1 Ypos 0 - n
Line 2
Toshiba T6963 LCD. (8-bit Font mode)
Xpos 0 - n msb lsb
Line 0
Line 1 Ypos 0 - n
Line 2
Toshiba T6963 LCD. (6-bit Font mode) There are important differences between the KS0108 and Toshiba screen formats. The diagrams below show these in more detail: -
The diagram below illustrates the position of one byte at position 0,0 on a KS0108 LCD screen. The least significant bit is located at the top. The byte displayed has a value of 149 (10010101).
The diagram below illustrates the position of one byte at position 0,0 on a Toshiba T6963 LCD screen in 8-bit font mode. The least significant bit is located at the right of the screen byte. The byte displayed has a value of 149 (10010101).
The diagram below illustrates the position of one byte at position 0,0 on a Toshiba T6963 LCD screen in 6-bit font mode. The least significant bit is located at the right of the screen byte. The byte displayed still has a value of 149 (10010101), however, only the first 6 bits are displayed (010101) and the other two are discarded.