'===== PICnLCD.BAS =================================================== BX-24 ==
'
' This module contains routines for the PIC-n'-LCD 4x20 serial LCD module.
' It assumes the LCD input is connected to BX-24 pin-1
'
' 1999/11/02  Created by Nick Taylor  ntaylor@iname.com
' 1999/11/04  Added LCDPutByte() & LCDPutStr()
'
' Requires:
'    SerialPort_24.bas
'    Support_24.bas
'
' The PICnLCD module by Dale Wheat is available from:
'   Peter Anderson at:  http://www.phanderson.com
'   B.G. Micro at:  http://www.bgmicro.com
'------------------------------------------------------------------------------
' PICnLCD commands:
' &h01 - Cursor Address - Next byte is the location on the LCD panel:
'          &h00 - 00 - beginning of line 1
'          &h40 - 64 - beginning of line 2
'          &h14 - 20 - beginning of line 3
'          &h54 - 84 - beginning of line 4
' &h02 - Home Cursor - Moves cursor to location 00, does not affect display.
' &h03 - Cursor Left - Moves cursor one position left.  Nondestructive.
' &h04 - Cursor Right - Moves cursor one position right.  Nondestructive.
' &h05 - Save Cursor Position - Saves the current cursor position.
' &h06 - Restore Cursor Position - Restores cursor to previously stored address.
' &h07 - Bell - Sounds tone for about 0.1 seconds.
' &h08 - Backspace - Destructive backspace.
' &h09 - Horizontal Tab - Advances cursor four places to the right.
' &h0A - Line Feed - Moves cursor to the same position on the next line.
' &h0B - Vertical Tab - The display scrolls up one line.  Cursor doesn't move.
' &h0C - Form Feed - Clears display and homes cursor.
' &h0D - Carriage Return - Moves cursor to beginning of current line.
' &h0D - Shift Left - Entire display shifts one place left.
' &h0F - Shift Right - Entire display shifts one place right.
' &h11 - Send LCD Instruction - Next byte is sent to the instruction register.
' &h12 - Send LCD Data - Next byte is displayed.
' &h13 - Set Number of Lines - Next bytes sets number of lines (4 is default).
' &h15 - General Purpose Output - Next byte is GP0 thru GP4.
' &h16 - Print Signed Decimal Number - Displays next byte as signed decimal.
' &h17 - Print Unsigned Decimal Number - Displays next byte as unsigned decimal.
' &h19 - Set Cursor Display Options - Next byte defines cursor style.
'          &h00 - no cursor
'          &h01 - blinking block
'          &h02 - underline
'          &h03 - blinking block and underline
'==============================================================================
' Cursor type commands for use by LCDCursorType(type)
public const None as BYTE = &h00
public const BlinkBlock as BYTE = &h01
public const Underline as BYTE = &h02
public const BlockUnderline as BYTE = &h03
'------------------------------------------------------------------------------
public sub LCDInit()
   ' Open pin-1 for 9600 baud.
   CALL OpenSerialPort_1(9600)
   ' Turn LEDs off.
   CALL LCDPutByte(&h15)
   CALL LCDPutByte(&h00)
   ' Clear the screen.
   CALL LCDPutByte(&h0C)
   ' Set the cursor to disabled.
   CALL LCDPutByte(&h19)
   CALL LCDPutByte(&h00)
   ' Move the cursor to row 2, col 3.
   CALL LCDPutByte(&h01)
   CALL LCDPutByte(&h43)
END sub
'------------------------------------------------------------------------------
public sub LCDCursorType( _
   ByVal Type as BYTE)

' Sets the cursor type.

   CALL LCDPutByte(&h19)
   CALL LCDPutByte(Type)
END sub
'------------------------------------------------------------------------------
public sub LCDClearScreen()

' Clears the screen and homes the cursor.

   CALL LCDPutByte(&h0C)
END sub
'------------------------------------------------------------------------------
public sub LCDHomeCursor()

' Moves cursor to row 1, col 1.

   CALL LCDPutByte(&h02)
END sub
'------------------------------------------------------------------------------
public sub LCDPutCursor( _
   ByVal Line as BYTE, _
   ByVal Column as BYTE)

' Moves the cursor to the commanded line (1-4) and row (1-20).

   IF ((Column < 1) OR (Column > 20)) THEN
      CALL LCDFail(1)
   END IF
   CALL LCDPutByte(&h01)
   SELECT CASE Line
      CASE 1
         CALL LCDPutByte(Column - 1)
      CASE 2
         CALL LCDPutByte(64 + Column - 1)
      CASE 3
         CALL LCDPutByte(20 + Column - 1)
      CASE 4
         CALL LCDPutByte(84 + Column - 1)
      CASE ELSE
         CALL LCDFail(2)
   END SELECT
END sub
'------------------------------------------------------------------------------
public sub LCDBackspace()

' Does a single destructive backspace.

   CALL LCDPutByte(&h08)
END sub
'------------------------------------------------------------------------------
public sub LCDPutByte( _
   ByVal n as BYTE)

   CALL PutByte_1(n)
END sub
'------------------------------------------------------------------------------
public sub LCDPutStr( _
   ByRef txt as STRING)

   CALL PutStr_1(txt)
END sub
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
private sub LCDFail( _
   ByVal flashes as BYTE)

' Flashes the on chip LEDs to indicate a failure.  Two green flashes indicate
' the PICnLCD followed by one red flash for a column error or two flashes for
' a row error.

   CALL PutPin(GreenLED, 1)	' Green LED off.
   CALL PutPin(RedLED, 1)	' Red LED off.
   DO
      CALL FlashLED(GreenLED, 2)
      CALL FlashLED(RedLED, flashes)
   LOOP
END sub
'==============================================================================