Basic Micro Studio Syntax Manual

Commands
Custom Characters
Most HD44780 controllers provide room for 8 user defi nable characters, they are ASCII values 0 to
7. The programmable characters are 5x8 pixels. There are 8 bytes for each custom character. The
bytes are arranged in a grid to defi ne the new character. The custom characters can be used to make
sprites that can then be used to form larger characters that are made up of multiple locations and
spread across more than one display line. The fi rst 3 bits are ignored (7-5), only bits 4-0 are used to
defi ne the character. An on pixel is expressed with a 1 and off is 0.
Bits -> 4 3 2 1 0 Binary Hex Decimal
Byte 0 00000000 00 00
Byte 1 00001010 0A 10
Byte 2 00001010 0A 10
Byte 3 00001010 0A 10
Byte 4 00000000 00 00
Byte 5 00010001 11 17
Byte 6 00001110 0E 14
Byte 7 00000000 00 00
Example
To write and display the custom characters shown above, you would use the LCDWRITE command
with the CGRAM function. The following code snippet will write and display the custom character
shown above on a 2x16 LCD display. Connect LCD using the schematics shown for LCDINIT.
lcdinit p0\p1\p7\p6\p5\p4
lcdwrite p0\p1\p7\p6\p5\p4,[cgram+0,0x00,0x0A,0x0A,0x0A,0x00,0x11,0x0E,0x00,scrram+0]
Using our newly created custom character, the below sample program will clear the screen and
starting from the home position print “Hello Word!”.
lcdinit p0\p1\p7\p6\p5\p4
;create custom character
lcdwrite p0\p1\p7\p6\p5\p4,[cgram+0,0x00,0x0A,0x0A,0x0A,0x00,0x11,0x0E,0x00,scrr
am+0]
;clear screen, home cursor, print “Hello World!” and custom character
lcdwrite p0\p1\p7\p6\p5\p4,[lcdclear,lcdhome,”Hello World! “,0]
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