lcd-hd44780
Generic driver for HD44780 based LCDs
lcd-hd44780
MCU-independent LCD driver for the common HD44780 and its ubiquitous clones.
Setup
Reading the display data is not supported, that way RW can be tied to GND and one can directly drive E, RS, D7-D4 with a 3.3V MCU
Before including the library, define theese three words. You can also check out the demo file for a simple implementation.
lcd-nibble ( x -- )send a nibble to the LCD (set D7-D4 and strobe E)lcd-mode-data ( -- )data mode (clear RS)lcd-mode-cmd ( -- )data mode (set RS)
Once the required words are defined and the library is included, using it is as easy as typing the following:
-1 lcd-init
lcd( Hi there!)
Usage / Words
lcd-emit ( x -- )
send byte to display
Example Show 'A': CHAR A lcd-emit
lcd-cmd ( x -- )
send command to display
(used by subsequent lcd-* words)
lcd-clear ( -- )
clear display content
lcd-home ( -- )
move cursor to home position
lcd-entry-mode ( f-I/D f-S -- )
I/D=1 increment or I/D=0 decrement address after write,
S=1 shift entire display to I/D direction
Example Increment on store, do not shift -1 0 lcd-entry-mode
lcd-display-control ( f-D f-C f-B -- )
D=1 display on, D=0 off
C=1 cursor on, C=0 off
B=1 cursor blink on, B=0 off
Example disable display: 0 0 0 lcd-display-control
Example enable display, show non-blinking cursor: -1 -1 0 lcd-display-control
lcd-c/d-shift ( f-S/C f-R/L -- )
S/C=1 display shift, S/C=0 cursor shift
R/L=1 to the right, R/L=0 to the left
lcd-function-set ( f-DL f-N f-F -- )
DL=1 8 bit, DL=0 4 bit data length
N=1 2 lines, N=0 1 line
F=1 5x10 dots, F=0 5x8 fots
lcd-cgram ( u-addr -- )
set Character Generator RAM address
(used to handle custom characters, see lcd-char)
lcd-ddram ( u-addr -- )
set Display Data RAM address (sets the cursor position)
Example go to 2nd line on a 2-line display or 3rd line on a 4-line display: $40 lcd-ddram
Hint: A 2-line display has the 1st line at DDRAM $00, the 2nd at $40.
A 4-line display has the 1st line at DDRAM $00, 2nd at $20, 3rd at $40, 4th at $60.
lcd-init ( f-lines -- )
initialize 4 bit interface
Example Initialize a multi-line LCD: -1 lcd-init
lcd-type ( c-addr n -- )
send string to display
Example s" text" lcd-type
lcd( ( -- )
like .( but send to lcd
Example lcd( Forth rocks)
lcd" ( -- )
like ." but send to lcd
Example : hi lcd" Hello" ;
lcd. ( -- )
number output
Example 42 lcd.
lcd-char ( c-addr u-char -- )
Define a custom character, c-addr points to an address containing 8 consecutive pattern codes.
u-char must be between [0,7].
Example Hourglass as custom character 4:
\ each byte represents a line starting from top to bottom
create hourglass-data $1F c, $11 c, $0A c, $04 c, $0A c, $11 c, $1F c, $00 c,
\ send custom character to LCD
hourglass-data 4 lcd-char
\ display the character at the current DDRAM-position
4 lcd-emit
