5: BASIC Stamp Command Reference – LCDCMD
BASIC Stamp Programming Manual 2.0c • www.parallaxinc.com • Page 159
LCDCMD
BS1 BS2 BS2e BS2sx BS2p
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. 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
BS2p
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.
Explanation
The three LCD commands (LCDCMD, LCDIN and LCDOUT) allow the
BS2p 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
instructions to the LCD. It is most commonly used to initialize the display
upon a power-up or reset condition.
The following is an example of the LCDCMD command:
LCDCMD 1, 24
Table 5.26: LCDCMD Quick Facts.
2
A SIMPLE LCDCMD EXAMPLE.
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