27220 Parallax Inc, 27220 Datasheet - Page 89

• Manufacturer Part Number: 27220
• Description: BOOK STAMPWORKS
• Manufacturer: Parallax Inc

Specifications of 27220

• Accessory Type: Booklet
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• For Use With/related Products: StampWorks
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Not applicable / Not applicable

' -----[ Subroutines ]-----------------------------------------------------
LCD_Cmd:
LCD_Out:
Behind the Scenes
This is a very simple program which demonstrates the essential functions of a
character LCD. The LCD is initialized using four-bit mode in accordance with the
Hitachi HD44780 controller specifications. This mode is used to minimize the number
of BASIC Stamp I/O lines needed to control the LCD. While it is possible to connect
to and control the LCD with eight data lines, this will not cause an appreciable
improvement in program performance and will use four more I/O lines; for most
projects it is better to conserve I/O.
The basics of the initialization are appropriate for most applications:
FOR idx = 1 TO 16
NEXT
PAUSE 1000
GOTO Main
LOW RS
LcdBus = char.HIGHNIB
PULSOUT E, 3
LcdBus = char.LOWNIB
PULSOUT E, 3
HIGH RS
RETURN
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char = LcdDispL
GOSUB LCD_Cmd
PAUSE 100
The display is on
The underline cursor is off
The blinking cursor is off
The cursor is automatically incremented after each write
The display does not shift
' shift display back
' do it all over
' enter command mode
' output high nibble
' strobe the Enable line
' output low nibble
' return to character mode