Action
Instruct the compiler to generate code for 8-bit LCD displays attached to the data bus.
Syntax
$LCDRS = [&H]address
Remarks
Address |
The address where must be written to, to enable the LCD display.
The db0-db7 lines of the LCD must be connected to the data lines D0-D7. (or is 4 bit mode, connect only D4-D7)
On systems with external RAM, it makes more sense to attach the LCD to the data bus. With an address decoder, you can select the LCD display. |
The compiler will create a constant named ___LCDRS_ADR which you could use in an alternative LCD library.
See also
Example
'--------------------------------------------------------------
' (c) 1995-2021 MCS Electronics
'--------------------------------------------------------------
' file: LCD.BAS
' demo: LCD, CLS, LOWERLINE, SHIFTLCD, SHIFTCURSOR, HOME
' CURSOR, DISPLAY
'--------------------------------------------------------------
'note : tested in bus mode with 4-bit on the STK200
'LCD - STK200
'-------------------
'D4 D4
'D5 D5
'D6 D6
'D7 D7
'WR WR
'E E
'RS RS
'+5V +5V
'GND GND
'V0 V0
' D0-D3 are not connected since 4 bit bus mode is used!
'Config Lcdpin = Pin , Db4 = Portb.1 , Db5 = Portb.2 , Db6 = Portb.3 , Db7 = Portb.4 , E = Portb.5 , Rs = Portb.6
Rem with the config lcdpin statement you can override the compiler settings
$regfile = "8515def.dat"
$lcd = &HC000
$lcdrs = &H8000
Config Lcdbus = 4
Dim A As Byte
Config Lcd = 16 * 2 'configure lcd screen
'other options are 16 * 2 , 16 * 4 and 20 * 4, 20 * 2 , 16 * 1a
'When you dont include this option 16 * 2 is assumed
'16 * 1a is intended for 16 character displays with split addresses over 2 lines
'$LCD = address will turn LCD into 8-bit databus mode
' use this with uP with external RAM and/or ROM
' because it aint need the port pins !
Cls 'clear the LCD display
Lcd "Hello world." 'display this at the top line
Wait 1
Lowerline 'select the lower line
Wait 1
Lcd "Shift this." 'display this at the lower line
Wait 1
For A = 1 To 10
Shiftlcd Right 'shift the text to the right
Wait 1 'wait a moment
Next
For A = 1 To 10
Shiftlcd Left 'shift the text to the left
Wait 1 'wait a moment
Next
Locate 2 , 1 'set cursor position
Lcd "*" 'display this
Wait 1 'wait a moment
Shiftcursor Right 'shift the cursor
Lcd "@" 'display this
Wait 1 'wait a moment
Home Upper 'select line 1 and return home
Lcd "Replaced." 'replace the text
Wait 1 'wait a moment
Cursor Off Noblink 'hide cursor
Wait 1 'wait a moment
Cursor On Blink 'show cursor
Wait 1 'wait a moment
Display Off 'turn display off
Wait 1 'wait a moment
Display On 'turn display on
'-----------------NEW support for 4-line LCD------
Thirdline
Lcd "Line 3"
Fourthline
Lcd "Line 4"
Home Third 'goto home on line three
Home Fourth
Home F 'first letteer also works
Locate 4 , 1 : Lcd "Line 4"
Wait 1
'Now lets build a special character
'the first number is the characternumber (0-7)
'The other numbers are the rowvalues
'Use the LCD tool to insert this line
Deflcdchar 1 , 225 , 227 , 226 , 226 , 226 , 242 , 234 , 228 ' replace ? with number (0-7)
Deflcdchar 0 , 240 , 224 , 224 , 255 , 254 , 252 , 248 , 240 ' replace ? with number (0-7)
Cls 'select data RAM
Rem it is important that a CLS is following the deflcdchar statements because it will set the controller back in datamode
Lcd Chr(0) ; Chr(1) 'print the special character
'----------------- Now use an internal routine ------------
_temp1 = 1 'value into ACC
!rCall _write_lcd 'put it on LCD
End