I'm trying to read a graphic LCD, it seems to have 128 x 64 dots. It communicates with an ARM STM32F103 via SPI. I intercepted the communication between the LCD module and MCU, and decoded part of the communication.

I would like to know: How can I discover the model of the LCD controller that this LCD module uses?

I need to read it, so, I need to know which controller it uses and which pins are available in the flat cable connector.

Does someone have a tip, or any advice?

Here are some pictures of it.

(click for larger images)

Image 1

Image 2

  • \$\begingroup\$ it should say on the chip, unless it's potted or scraped. also, there's only a half-dozen or so popular lib bundles; try them. \$\endgroup\$
    – dandavis
    May 16, 2018 at 0:34
  • \$\begingroup\$ @dandavis LCD controllers are often COG, and those are usually unmarked. \$\endgroup\$
    – user39382
    May 16, 2018 at 2:31

1 Answer 1


It's hard to tell the controller which is been used by the chip. Many random LCD won't have some valid LCD part number where you can google and search it. Only thing you can do is try to reverse engineer the LCD, as you found its SPI and program a microcontroller with the same SPI data and check for it's correctness. If that works then, then dig deeper with the LCD with different patterns and program it.

The only way to know to drive these kind of random LCD is reverse engineering with MSO ,collect the data and analyse the data and check for it's correctness using a microcontroller ,interface with that LCD and check with the data that you analysed. It takes more time to reverse engineer these kinds of LCD but still it's possible do it. I also reverse engineed an random LCD which came with phone(dotted LCD) . It really took very long time to understand the protocol, it's function and still there is literally more things that I have to explore with that LCD. It doesn't end at all.


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