I bought some text LCD modules without spec sheets or obvious part numbers. They all have a series of connector pins, unlabelled other than a 1 to indicate pin 1. I was able to get the one with a Hitachi driver and 16 pins to work fine, and now I'm trying to get a 9-pin lcd to work.

Is there a standard pinout for most 9-pin LCDs?

Pin 8 is clearly A for anode, possibly for backlight. Pin 9 is K for cathode, again possibly for backlight. The other 7 pins are unlabelled besides the 1 and 9 indicating pin numbering.

There is a sticker on the back that reads:


And another that says 847845740. There is a Samsung logo as well. The controller circuit is covered with that hard black protective material that I typically see on cheap devices, so I can't see the controller at all.

If the faint outline I can see on the screen is right, it looks like its 16 columns x 4 rows.

  • \$\begingroup\$ The black lump on the back of the display module is most likely covering the display controller chip and not a general MCU. \$\endgroup\$ Jan 7, 2014 at 11:27
  • \$\begingroup\$ @MichaelKaras Right. Edited the post, as I meant the display controller. \$\endgroup\$
    – Mar
    Jan 7, 2014 at 19:48

1 Answer 1


A search for UC164904 lead to this page which shows a 20x4 SPI LCD

enter image description here

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  • \$\begingroup\$ That looks like it has 1 data pin instead of 4 or 8 like the standard 16-pin lcds. I'm guessing Arduino's LiquidCrystal library won't work with that as-is? \$\endgroup\$
    – Mar
    Jan 7, 2014 at 20:00
  • \$\begingroup\$ @mouseas This is a new question so you shouldn't add it as a comment to an answer. alexan_e was kind enough to search for your LCD's part number for you but you shouldn't assume that alexan_e is also familiar with Arduino libraries. The best approach is to open a new question and give it an Arduino tag. That's also more helpful to other visitors to EE.SE. \$\endgroup\$
    – Joe Hass
    Jan 7, 2014 at 21:05
  • 1
    \$\begingroup\$ @mouseas The SPI protocol has two data pins (MISO/MOSI), one clock (SCLK) plus one chip select (CS). As joe suspects I'm not familiar with arduino since I code using avrstudio but if your library is meant to be used with the classic 4/8bit data lines then it will not work unless you modify it. \$\endgroup\$
    – alexan_e
    Jan 7, 2014 at 21:20
  • \$\begingroup\$ Just knowing that it is set up for SPI protocol helps a ton. Thanks! \$\endgroup\$
    – Mar
    Jan 8, 2014 at 17:09

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