BASIC stamp manual v2.2

5: BASIC Stamp Command Reference – LCDCMD
BASIC Stamp Syntax and Reference Manual 2.2 • www.parallax.com • Page 249
LCDCMD
BS1 BS2 BS2e BS2sx BS2p BS2pe BS2px
LCDCMD Pin, Command
Function
Send a command to an LCD display.
• Pin is a variable/constant/expression (0 – 1 or 8 – 9) that specifies
which I/O pins to use. The LCD requires, at most, seven I/O pins
to operate. Note that LCDCMD, LCDIN and LCDOUT use a 4-bit
interface to the LCD which requires a specific initialization sequence
before LCDIN and LCDOUT can be used. Specifics on the
initialization sequence will follow. The Pin argument serves a
double purpose; specifying the first pin and, indirectly, the group of
other required pins. See explanation below. All I/O pins will be set
to output mode.
• Command is a variable/constant/expression (0 – 255) indicating the
LCD command to send.
Quick Facts
Table 5.43: LCDCMD Quick Facts.
BS2p, BS2pe, and BS2px
Values for Pin
0, 1, 8 or 9
I/O Pin
Arrangement
when Pin is
0 or 1
0 or 1 (depending on pin): LCD Enable (E) pin
2: LCD Read/Write (R/W) pin
3: LCD Register Select (RS) pin
4 – 7: LCD Data Buss (DB4 – DB7, respectively) pins
I/O Pin
Arrangement
when Pin is
8 or 9
8 or 9 (depending on pin): LCD Enable (E) pin
10: LCD Read/Write (R/W) pin
11: LCD Register Select (RS) pin
12 – 15: LCD Data Buss (DB4 – DB7, respectively) pins
Special Notes
LCDCMD is designed to use the LCD's 4-bit mode only.
Related Commands
LCDIN and LCDOUT
Explanation
The three LCD commands (LCDCMD, LCDIN and LCDOUT) allow the
BS2p, BS2pe, and BS2px to interface directly to standard LCD displays that
feature a Hitachi 44780 controller (part #HD44780A). This includes many
1 x 16, 2 x 16 and 4 x 20 character LCD displays.
The Hitachi 44780 LCD controller supports a number of special
instructions for initializing the display, moving the cursor, changing the
default layout, etc. The LCDCMD command is used to send one of these
NOTE: LCDCMD, LCDIN and
LCDOUT use a 4-bit interface to the
LCD which requires a specific
initialization sequence before LCDIN
and LCDOUT can be used; read more
below.