LCD Line 2

Microman171 · 2006-02-26 08:30

I have a parallel LCD and i have no idea how to access the second line

This is my code so far:

' =========================================================================
'
'   File....... SW20-EX11-LCD_Demo.BS2
'   Purpose.... Essential LCD control
'   Author..... (C) 2000 - 2005, Parallax, Inc.
'   E-mail..... support@parallax.com
'   Started....
'   Updated.... 01 JUN 2005
'
'   {$STAMP BS2}
'   {$PBASIC 2.5}
'
' =========================================================================


' -----[noparse][[/noparse] Program Description ]---------------------------------------------
'
' This program demonstrates essential character LCD control.
'
' The connections for this program conform to the BS2p-family LCDCMD,
' LCDIN, and LCDOUT instructions.  Use this program for the BS2, BS2e,
' or BS2sx.  There is a separate program for the BS2p, BS2pe, and BS2px.


' -----[noparse][[/noparse] I/O Definitions ]-------------------------------------------------

E               PIN     1                       ' Enable pin
RW              PIN     2                       ' Read/Write
RS              CON     3                       ' Register Select
LcdBus          VAR     OUTB                    ' 4-bit LCD data bus


' -----[noparse][[/noparse] Constants ]-------------------------------------------------------

LcdCls          CON     $01                     ' clear the LCD
LcdHome         CON     $02                     ' move cursor home
LcdCrsrL        CON     $10                     ' move cursor left
LcdCrsrR        CON     $14                     ' move cursor right
LcdDispL        CON     $18                     ' shift chars left
LcdDispR        CON     $1C                     ' shift chars right

LcdDDRam        CON     $80                     ' Display Data RAM control
LcdCGRam        CON     $40                     ' Character Generator RAM
LcdLine1        CON     $80                     ' DDRAM address of line 1
LcdLine2        CON     $C0                     ' DDRAM address of line 2


#DEFINE LcdReady = ($STAMP >= BS2P)


' -----[noparse][[/noparse] Variables ]-------------------------------------------------------

char            VAR     Byte                    ' character sent to LCD
idx             VAR     Byte                    ' loop counter
idx2            VAR     Byte                    ' loop counter2


' -----[noparse][[/noparse] EEPROM Data ]-----------------------------------------------------

Msg             DATA    "Line1", 0   ' store message
Msg2            DATA    "Line2", 0   ' store message2


' -----[noparse][[/noparse] Initialization ]--------------------------------------------------

Reset:
  #IF (LcdReady) #THEN
    #ERROR "Please use BS2p version: SW20-EX11-LCD_Demo.BSP"
  #ENDIF

  DIRL = %11111110                              ' setup pins for LCD
  PAUSE 1000                                    ' let the LCD settle

Lcd_Setup:
  LcdBus = %0011                                ' 8-bit mode
  PULSOUT E, 3
  PAUSE 5
  PULSOUT E, 3
  PULSOUT E, 3
  LcdBus = %0010                                ' 4-bit mode
  PULSOUT E, 1
  char = %00101000
  GOSUB LCD_Cmd
  char = %00001100                              ' disp on, no crsr or blink
  GOSUB LCD_Cmd
  char = %00000110                              ' inc crsr, no disp shift
  GOSUB LCD_Cmd


' -----[noparse][[/noparse] Program Code ]----------------------------------------------------

Main:
  char = LcdCls                                 ' clear the LCD
  GOSUB LCD_Cmd
  PAUSE 500
  idx = Msg                                       ' get EE address of message
  idx2 = Msg2                                     ' get EE address of message2

Write_Message:
  DO
    READ idx, char                              ' get character from EE
    IF (char = 0) THEN EXIT                     ' if 0, message is complete
    GOSUB LCD_Out                               ' write the character
    idx = idx + 1                               ' point to next character
  LOOP
  PAUSE 2000                                    ' wait 2 seconds

Write_MessageLine2:
  DO
    char = LcdDDRam
    READ idx, char                              ' get character from EE
    IF (char = 0) THEN EXIT
    char = LcdLine2                     ' if 0, message is complete
    GOSUB LCD_Out                               ' write the character
    idx = idx + 1                               ' point to next character
  LOOP
  PAUSE 2000                                    ' wait 2 seconds

Cursor_Demo:
  char = LcdHome                                ' move the cursor home
  GOSUB LCD_Cmd
  char = %00001110                              ' turn the cursor on
  GOSUB LCD_Cmd
  PAUSE 500

  char = LcdCrsrR
  FOR idx = 1 TO 15                             ' move cursor l-to-r
    GOSUB LCD_Cmd
    PAUSE 150
  NEXT

  FOR idx = 14 TO 0                             ' move cursor r-to-l by
    char = LcdDDRam + idx                       '  moving to a specific
    GOSUB LCD_Cmd                               '   column
    PAUSE 150
  NEXT

  char = %00001101                              ' cursor off, blink on
  GOSUB LCD_Cmd
  PAUSE 2000

  char = %00001100                              ' blink off
  GOSUB LCD_Cmd

Flash_Demo:
  FOR idx = 1 TO 10                             ' flash display
    char = char ^ %00000100                     ' toggle display bit
    GOSUB LCD_Cmd
    PAUSE 250
  NEXT
  PAUSE 1000

Shift_Demo:
  FOR idx = 1 TO 16                             ' shift display
    char = LcdDispR
    GOSUB LCD_Cmd
    PAUSE 100
  NEXT
  PAUSE 1000

  FOR idx = 1 TO 16                             ' shift display back
    char = LcdDispL
    GOSUB LCD_Cmd
    PAUSE 100
  NEXT
  PAUSE 1000

  GOTO Main                                     ' do it all over


' -----[noparse][[/noparse] Subroutines ]-----------------------------------------------------

LCD_Cmd:
  LOW RS                                        ' enter command mode


LCD_Out:
  LcdBus = char.HIGHNIB                         ' output high nibble
  PULSOUT E, 3                                  ' strobe the Enable line
  LcdBus = char.LOWNIB                          ' output low nibble
  PULSOUT E, 3
  HIGH RS                                       ' return to character mode
  RETURN

I plan to take out all the flashy stuff and have it so the LCD writes to both lines. I am sure the code is there EG


char = LcdLine2

But I don't know how to incorperate it so it actually does what is says :goes to the 2nd line.

If there is ANYTHING you need to know to further aid your assistance please do ask

Microman171

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1 + 1 = 10 Base 2
2 + 2 = 10 Base 4
3 + 3 = 10 Base 6
4 + 4 = 10 Base 8
5 + 5 = 10 Base 10

Post Edited (Microman171) : 2/26/2006 5:40:21 PM GMT

Jon Williams · 2006-02-26 14:32

That program is for a parallel LCD interface.· What brand/model serial LCD do you have?· If it's a Parallax serial LCD then the program I've attached will show you the way.

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Jon Williams
Applications Engineer, Parallax

Microman171 · 2006-02-26 17:40

oops thats what I meant

I have fixed up my post. Sorry for any confusion.

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1 + 1 = 10 Base 2
2 + 2 = 10 Base 4
3 + 3 = 10 Base 6
4 + 4 = 10 Base 8
5 + 5 = 10 Base 10

Jon Williams · 2006-02-26 17:43

The answer lies in the next chapter.· You'll see a small addition to the initialization section for mulit-line displays.· The code below was lifted from Experiment 12:

Lcd_Setup:
· LcdBus = %0011······························· ' 8-bit mode
· PULSOUT E, 3
· PAUSE 5
· PULSOUT E, 3
· PULSOUT E, 3
· LcdBus = %0010······························· ' 4-bit mode
· PULSOUT E, 1
· char = %00101000····························· ' multi-line mode
· GOSUB LCD_Cmd
· char = %00001100····························· ' disp on, no crsr or blink
· GOSUB LCD_Cmd
· char = %00000110····························· ' inc crsr, no disp shift
· GOSUB LCD_Cmd

With the proper initialization sequence you can move the LCD to that line with:

· char = LcdLine2
· GOSUB Lcd_Cmd

In short, study Experiment 12 to see how to write to both lines of a 2-line display.

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Jon Williams
Applications Engineer, Parallax

Post Edited (Jon Williams (Parallax)) : 2/26/2006 5:47:03 PM GMT

Microman171 · 2006-02-26 17:50

Thanks for replying so quickly

You caught BEFORE I left for school.

BTW where do I put the LcdLine2 command. A little stuck

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1 + 1 = 10 Base 2
2 + 2 = 10 Base 4
3 + 3 = 10 Base 6
4 + 4 = 10 Base 8
5 + 5 = 10 Base 10

Post Edited (Microman171) : 2/26/2006 5:53:14 PM GMT

musicbox · 2006-03-24 08:11

Hi Jon, I tried your Serial_LCD_Demo.BS2.TXT·to test out my LCD.· But all I am getting is garbage.
I have the Basic Stamp II educational board and Seetron's BPI-216 LCD.· I don't know what's going on.
Can you help me with this?

PJAllen · 2006-03-24 13:13

musicbox,

Seetron's BPI-216 is a SERIAL LCD, the programming in this thread (Jon's, et al.) concerns parallel LCDs.· You write to your SERIAL LCD using SEROUT instructions.

Chris Savage · 2006-03-24 15:28

musicbox said...
Hi Jon, I tried your Serial_LCD_Demo.BS2.TXT·to test out my LCD.· But all I am getting is garbage.
I have the Basic Stamp II educational board and Seetron's BPI-216 LCD.· I don't know what's going on.
Can you help me with this?

Please start your own thread on this subject.

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Chris Savage
Parallax Tech Support
csavage@parallax.com

LCD Line 2

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