[Solved] Column Start Address = 0x1C? (Column Addressing on NHD-3.12-25664)

___brad

• May 16, 2020 21:31

I'm having difficulty understanding how pixels/columns are addressed. The sample code at https://support.newhavendisplay.com/hc/en-us/articles/4413326606999-NHD-2-8-25664UCxx  for example, uses 0x1C as the start address and 0x5B as the end for a full screen scan. For a 256 pixel OLED, why wouldn't the start address be 0x00 and the end be 0xFF?

The SSD1322 spec suggests that each column represents 4 pixels. But if that's true then why wouldn't the end address be 0x3F?

I know I'm missing something basic. Any help would be appreciated.

Thanks,
Brad

 

« Last Edit: May 21, 2020, 01:23:07 PM by ___brad »

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  Alee_S

  • May 21, 2020 08:33

  Hi Brad,
  
  The reason for the start and end address's being 0x1C and 0x5B respectively are based on which Segment lines from the SSD1322 controller are directly connected to the display. The mechanical drawing on pg. 3 of the display datasheet shows the display SEG orientation from Segment 112 - 357 (should be 367, will be corrected on our online specs asap), and this corresponds to the start and end address being 0x1C and 0x5B as a result. Had the display lines instead been connected using Segments 0 - 256, the start address would be 0x00 and the end address would 0x3F.
  Datasheet: https://newhavendisplay.com/content/specs/NHD-3.12-25664UCY2.pdf 
  
  Each byte will write to 2 pixels on the screen, and 4 bits will correspond to 1 pixel.
  
  Best regards,

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  ___brad

  • May 21, 2020 13:24

  Ahhh. Makes sense. Thanks Alee_S!

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