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Parallel LCD program — Parallax Forums

Parallel LCD program

ArchiverArchiver Posts: 46,084
edited 2004-05-06 22:23 in General Discussion
I have an LCD from a HP printer. It has a Hitachi (?) chip HD44780S on the
back and 14 pins on the left edge. I would like to write a program for my
Stamp to convert this to a serial LCD. Does anyone have such a program?
It looks like it is a 2 x 20.

Thanks

Sid Weaver


[noparse][[/noparse]Non-text portions of this message have been removed]

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2004-05-06 15:17
    In a message dated 5/6/2004 2:10:10 PM Eastern Daylight Time,
    klausdejong@x... writes:


    > Below you find (part of) the code I use for my Hitachi 2X8 and 2x16
    > displays. It is designed for 4 bit data transfer and 3 bit control
    > for the display. I normaly use pins 9, 10, 11 for the control and
    > 12,13,14,15 for the data.
    >
    >

    Thanks, Klaus. I'll see if I can puzzle out the code. One question, where
    do I connect the 14 pins on the LCD. They must go to the Stamp somewhere.

    Sid


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2004-05-06 19:06
    Hi Sid,

    Below you find (part of) the code I use for my Hitachi 2X8 and 2x16
    displays. It is designed for 4 bit data transfer and 3 bit control
    for the display. I normaly use pins 9, 10, 11 for the control and
    12,13,14,15 for the data.

    I hope this helps,

    Klaus

    A substantial part of the code below is "borrowed" from Jon
    Williams :-)

    >>>>>>>>>>>>>>>>>>>>>>>Example of sendtext
    'DISPLAY
    ' FOR idx = 2 TO 1
    ' char = Ts DIG idx + 48
    ' GOSUB SENDTEXT
    ' NEXT
    ' char = "."
    ' GOSUB SENDTEXT
    ' char = ts DIG 0 + 48

    '' GOSUB NEXT_LINE


    >>>>>>>>>>>>>>>>>>> initializing Display
    RS CON 9
    RW CON 10
    E CON 11

    CHAR VAR Byte
    INST VAR CHAR
    'INDEX VAR Word
    TEMP VAR Byte
    idx VAR Byte

    LOW RW
    OUTH = %00000000
    DIRH = %11111111
    GOSUB INITLCD
    'Einde Display initialisatie

    >>>>>>>>>>>>>>>>>>>>>>>>>Display numbers and characters
    Some Subroutine:
    GOSUB CLEARSCREEN

    FOR idx = 2 TO 1
    char = Temperatuur DIG idx + 48
    GOSUB SENDTEXT
    NEXT
    char = "."
    GOSUB SENDTEXT
    char = Temperatuur DIG 0 + 48
    GOSUB SENDTEXT
    char = 223
    GOSUB SENDTEXT
    char = "C"
    GOSUB SENDTEXT

    FOR idx = 1 TO 0
    char = Wind DIG idx + 48
    GOSUB SENDTEXT
    NEXT
    char = "B"
    GOSUB SENDTEXT
    char = "f"
    GOSUB SENDTEXT

    GOSUB NEXT_LINE
    Return
    >>>>>>>>>>>>>>>>>>>>>>>> Routine for Hitachi
    INITLCD:

    PAUSE 200

    LOW RS
    LOW RW

    OUTH = %00110000
    PULSOUT E,1 'INITIALISATIE DISPLAY
    PAUSE 10
    PULSOUT E,1
    PAUSE 1
    PULSOUT E,1
    PAUSE 1

    OUTH = %00100000
    PULSOUT E,1 'KIES 4-BIT TRANSFER

    INST = %00101000
    GOSUB SENDINST 'DISPLAY AAN, KIES 2 REGEL DISPLAY

    INST = %00001110
    GOSUB SENDINST 'CURSOR AAN

    INST = %00000001
    GOSUB SENDINST 'DISPLAY WISSEN

    INST = %00000110
    GOSUB SENDINST 'ENTRYMODE AUTOINCREMENT

    INST = 14
    GOSUB SENDINST 'CURSOR UNDERLINE
    RETURN

    CLEARSCREEN:
    INST = %00000001
    GOSUB SENDINST 'DISPLAY WISSEN
    RETURN

    SENDINST:
    PAUSE 1
    LOW RS
    OUTD=INST.HIGHNIB
    PULSOUT E,1
    OUTD=INST.LOWNIB
    PULSOUT E,1
    HIGH RS
    RETURN


    SENDTEXT:
    HIGH RS
    OUTD=CHAR.HIGHNIB
    PULSOUT E,1
    OUTD=CHAR.LOWNIB
    PULSOUT E,1
    RETURN

    NEXT_LINE:
    INST = 128+64
    GOSUB SENDINST
    RETURN

    Original Message
    From: <Newzed@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Thursday, May 06, 2004 4:22 PM
    Subject: [noparse][[/noparse]basicstamps] Parallel LCD program


    > I have an LCD from a HP printer. It has a Hitachi (?) chip
    HD44780S on
    the
    > back and 14 pins on the left edge. I would like to write a program
    for my
    > Stamp to convert this to a serial LCD. Does anyone have such a
    program?
    > It looks like it is a 2 x 20.
    >
    > Thanks
    >
    > Sid Weaver
    >
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the
    Subject and
    Body of the message will be ignored.
    >
    > Yahoo! Groups Links
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2004-05-06 22:23
    Hi Sid,

    In fact you can use only a nibble for the data and shift them into
    the LCD in two passes, that is pins 11,12,13,14 on the LCD. Pins
    4,5,6 on the LCD are for control tasks. Then pin 1 == GND, 2 == VDD
    and 3 == contrast. So pins 7,8,9,10 on the LCD are not used saving
    you 4 pins on the Stamp. This way you use only 7 instead of 11
    expensive I/O on your Stamp.

    Tip: search the web for HD44780 or KS0066

    Regards,

    Klaus

    PS it's a nice puzzle to get this working :-).

    --- In basicstamps@yahoogroups.com, Newzed@a... wrote:
    > In a message dated 5/6/2004 2:10:10 PM Eastern Daylight Time,
    > klausdejong@x... writes:
    >
    >
    > > Below you find (part of) the code I use for my Hitachi 2X8 and
    2x16
    > > displays. It is designed for 4 bit data transfer and 3 bit
    control
    > > for the display. I normaly use pins 9, 10, 11 for the control and
    > > 12,13,14,15 for the data.
    > >
    > >
    >
    > Thanks, Klaus. I'll see if I can puzzle out the code. One
    question, where
    > do I connect the 14 pins on the LCD. They must go to the Stamp
    somewhere.
    >
    > Sid
    >
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
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