US2066 compatibility with HD44780

TedM

I have some older equipment that uses a 2x20 LCD with an HD44780 4 bit parallel interface but I don't have access to the code to change the driver; it runs at 5 volts.  I like the idea of upgrading this equipment to a 2x20 OLED like the NHD-0220CW-AB3 that uses the US2066 driver; I skim-read the datasheet for the US2066 and it looks like it would be compatible:

1. It can run off a single 5V supply
2. It can run in 4-bit parallel mode with what looks like the same signal set, RS,RW,E
3. It seems that all the timing for the US2066 is in the nano Second range

Are the above assumptions OK? Am I right to think that I can run a US2066-based OLED off the unchanged HD44780  driver or will there be any issues with timing, initialization, etc?

If issues are likely, a (much) more complicated solution would be to insert a small PCB with processor that takes in the HD44780 commands and translates them to US2066, probably using I2C or SPI.

Thanks.

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Comments

5 comments

Date Votes
  • Alee_S

    Hi TedM!

    While the NHD-0220CW-AB3 can run off of a 5V supply and can be configured for 4-bit parallel mode, I am unable to confirm the timing durations, as these are not indicated in the command table.

    The commands, initialization, and timings of the HD44780 controller do vary from the US2066 controller, and will likely require a reconfiguration of your software for the US2066 controller instead.

    Linked below is sample code written for our US2066 controller using an Arduino for reference:
    https://github.com/NewhavenDisplay/NHD_US2066

    Best,

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  • TedM

    Thanks, I may try one and see what happens.

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  • pyke

    Have you tried? I'm curious to know if you succeed. I'm trying to do the same thing, to use this US20666 based OLED work in a HD44780 device without any change in the software.

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  • Vkellogg
    Hi. I have a similar question. I was told to use HD466780 but cannot find any in the colors I want. I'm hoping to use oled red on black 20x4 character displays.

    I've purchased these.  https://www.alliedelec.com/product/newhaven-display-international/nhd-0420cw-ar3/70518328/

    Any my goal is to use them with these.

    https://github.com/Ryzee119/OpenXenium/blob/master/INSTALLATION.md

    And this if needed

    https://github.com/Ryzee119/spi2par2019/blob/master/README.md

    If I need an additional adrino that's fine too, I'm confused by the difference in labeling, but I've been told to just use HD44780 lcd, however I can't find any in red, so I'd love to use your oleds if at all possible. I'm not smart enough to build circuits and software, but if a adrino exists and software I can buy and flash, and install.

    Please note I tried installing oled from open xenium spi connection, not sure if I did it right but I got nothing on the display.  Also tried wiring it in "4 bit"  mode with spi2spar and also had nothing on display.

    Thanks.
     
    « Last Edit: February 07, 2020, 03:16:05 PM by Vkellogg »
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  • Ted M.
    NHD Staff

    Hi Vkellogg,

    The software compatibility for the US2066 using code written for the HD44780 controller will vary on a case by case basis.  There is no way to predict if any given code will work on the US2066 controller without some timing changes in the users application's code until it is actually tested and debugged with this display in the end users device.

    Regards,

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