Parallax BASIC Stamp 2e, Programming Manual

Page: 164 / 353

LCDCMD - BASIC Stamp Command Reference
Page 162
•
BASIC Stamp Programming Manual 2.0b
•
www.parallaxinc.com
command and 64 is the location number. See the "Character Positioning"
section, below, for more information.
Command
(in decimal)
Description
Do Nothing 0 Don't perform any special operation.
Clear Display 1 Clear the display and move cursor to home position.
Home Display 2 Move cursor and display to home position.
Inc Cursor 6
Set cursor direction to right, without a display shift.
Display Off 8 Turn off display (display data is retained).
Display On 12 Turn on display without cursor (display is restored).
Blinking Cursor 13 Turn on display with blinking cursor.
Underline Cursor 14
Turn on display with underline cursor.
Cursor Left
16 Move cursor left one character.
Cursor Right 20 Move cursor right one character.
Scroll Left 24 Scroll display left one character.
Scroll Right 28 Scroll display right one character.
Move To CRAM
Address
64 + address
Move pointer to character RAM location
Move To DRAM
Address
128 + address
Move cursor to display RAM location
While most users will only need the commands shown in Table 5.27,
above, Table 5.28, below,
details all of the instructions supported by the
LCD (for advanced users). Many instructions are multipurpose,
depending on the state of special bits. Cleaver manipulation of the
instruction bits will allow for powerful control of the LCD.
The last command shown above (Move To DRAM Address) is used to
move the cursor to a specific position on the LCD. The LCD's DRAM
(Display RAM) is a fixed size with unique position number for each
character cell. The viewable portion of the DRAM depends on the LCD's
logical view position (which can be altered with the Scroll Display
command). The default view position is called the Home position; it
means that the display's upper left character corresponds to DRAM
location 0. Figure 5.13
indicates the position numbers for characters on the
LCD screen.
Note that Figure 5.13 shows the most common DRAM mapping, though
some LCD's may have organized the DRAM differently. A little
experimentation with your LCD may reveal this.
Table 5.27: Common LCD
Commands. These are supported
by LCDs with the Hitachi 44780
controller.
A
NOTE ABOUT ADVANCED
LCD
COMMANDS
.
C
HARACTER
P
OSITIONING
: M
OVING
THE CURSOR
.