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Optrex DMC20434 20x4 LCD Panel — Parallax Forums

Optrex DMC20434 20x4 LCD Panel

jeffjohnvoljeffjohnvol Posts: 197
edited 2013-09-17 12:37 in General Discussion
I bought a kit many years ago when I was considering getting into working with BX-24 chips.· I never did the development, but I still have this LCD panel.· It comes with instructions to use with a BX-24.

Has anyone here interfaced one of these with a stamp?· The instructions come with a 74hc595 serial shift register, so I assume that I would need to use it if I didn't want to use all of my outputs.

Picture of one:
http://cgi.ebay.com/Optrex-DMC20434-4x20-character-LCD-like-new-parallel-IF_W0QQitemZ110095854347QQihZ001QQcategoryZ26206QQcmdZViewItem

Specs
http://www.zap.org.au/elec2041-cdrom/board/doc/data/optrex-20x4-lcd-module.pdf

I've searched this forum for this and googled, but couldn't find anything related to a stamp solution.

Comments

  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2007-04-18 13:59
    Hi Jeff,
    If the LCD panel fits the defacto Hitachi standard for intialization, it is quite easy to use with a BasicStamp because the code has already been written and the Nuts & Volts articles have very clear explanitions.

    In another thread, you mention using the BS2. That is actually a 2nd choice for LCDs and the more advance stamps both have more room for code and PBasic supports LCD functions without having to write out every bitty thing.

    My own experience with buying other LCDs [noparse][[/noparse]not from Parallax] has been mixed. I bought a couple locally in Taiwan that have the same Hitachi intialization, but to my surprise I destroyed the first one because the Vdd and Vss were reversed.

    In sum, if you can get the original documentas and compare ALL the details - you will have a better outcome. LCDs last for about 2 seconds at reversed polarity. It doesn't matter if it is the correct voltage and well regulated.

    The 74hc595 serial shift register may have been provided to to reduce the Parallel Interface [noparse][[/noparse]which requires about 11 pins in full parallel] to a simple SHIFT IN interface. If you can use the 4bit input mode rather than the 8bit input mode, I would not bother with the shift register.

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    "If you want more fiber, eat the package.· Not enough?· Eat the manual."········
    ···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2007-04-18 14:04
    Hi again,
    It looks like the Hitachi standard is used [noparse][[/noparse]refers to HD44780 or equivalent in the documents]. It has 4 bit mode. Just make sure that you don't get your power lines reversed.

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    "If you want more fiber, eat the package.· Not enough?· Eat the manual."········
    ···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan
  • jeffjohnvoljeffjohnvol Posts: 197
    edited 2007-04-18 14:44
    Kramer said...
    Hi Jeff,
    If the LCD panel fits the defacto Hitachi standard for intialization, it is quite easy to use with a BasicStamp because the code has already been written and the Nuts & Volts articles have very clear explanitions.

    In another thread, you mention using the BS2. That is actually a 2nd choice for LCDs and the more advance stamps both have more room for code and PBasic supports LCD functions without having to write out every bitty thing.

    Thanks.· Yeah, I was thinking now about the BS2px.· Its only $30 more and seems to have some LCD commands.· It draws more power, but that shouldn't be a concern since it won't be running off of a battery.

    I have this one for free, if it toasts (hopefully not), no real loss, I'll just get another solution from Parallax that's tried and true.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2007-04-19 17:24
    Jeff,

    Code and wiring examples for Hitachi compatible LCD Displays can be found on our website at the following link. Take care.

    http://www.parallax.com/detail.asp?product_id=603-00006

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    Chris Savage
    Parallax Tech Support
  • prousselotprousselot Posts: 12
    edited 2013-09-17 12:37
    Chris Savage wrote: »
    Jeff,

    Code and wiring examples for Hitachi compatible LCD Displays can be found on our website at the following link. Take care.

    http://www.parallax.com/detail.asp?product_id=603-00006

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    Chris Savage
    Parallax Tech Support

    Hi Chris,

    I dug this thread from the past as I have the same lcd display. The link gave is not anymore valid. would you have by any chance a new link ?

    here is a link for the picture of the lcd http://lonvic.web.fc2.com/WorkShop/Optex_LCD/menu.html

    Thanks in advance

    Philippe
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