Bigger 2-Lane-MIPI displays

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Bigger 2-Lane-MIPI displays

Hi there!

I’m using the iPod Nano 6 1-Lane-MIPI display with the SSD2805 for some testing now and asked myself if there are some bigger displays available on the market like shown in the second picture on this blog:

Where can I get those or maybe bigger 4-Lane-MIPI displays with a controller, that is just as easy to control as the SSD2805? Or are there possibilities, to stack the SSD2805 like a shift register e.g.?

And how to connect the 2-Line-MIPI display with its connector to the SSD2805? Are there some breakout adapter boards with the correct connectors? I have no plan how they are named…

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Hi,

I’ve asked the author of the post to take look at this question.

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Hi

The bigger mipi LCD of 5" that you saw from the blog uses Video Mode, whereas the 1.5" iPodNano display uses Command Mode. By analogy with conventional LCDs, Command Mode is like the MCU-type display with CS, WR, DC, D[0:7] for interfacing. Video Mode is like RGB-type with vsync, hsync, pclk, and R[8]:G[8]:B[8] data lines.

As a result, although it is possible to drive the 1.5" iPodNano display with ESP32 alone, the same interface method cannot be applied to that 5" LCD of 480*854. It is not just the higher resolution. We need a converter, better say it, a display controller to change SPI/8080 to RGB output, then convert the RGB to 2-lane mipi output for high speed serial differential interface.

There are many solutions:

  1. ESP32 + SSD1963 + SSD2805. SSD1963 is to output RGB video which in turn feeding to SSD2805 for RGB>MIPI.
  2. ESP32+RA887x + SSD2805. Similar to method 1 but a different display controller with SPI input, and 2D functions etc.
  3. ESP32+EVE GPU (FT81x/BT81x) + SSD2805. This is an altogether different concept with (1) and (2) above because EVE GPU is a different beast than RA887x/SSD196x. Instead of using frame buffer for foreground/background graphics swapping, EVE GPU is more OpenGL inclined with something called Display List. Drawing by commands instead of pixels, this makes porting to LittlevGL very difficult. I tried it previously, but not successful. :sob:
  4. There are high end MCUs from ST with MIPI output built-in. It is STM32F7 series or something. In this case we just need:
    STM32F7 + 5" MIPI display directly. This is a much cleaner design but the cost of STM32F7 is also higher. Without ESP32 we have sacrificed Wifi and BLE too.

Internally I have tried method 3 above. Just for your interests two footages are available from:


But the footage was not produced by LittlevGL. Maybe some one in this forum know howto port it?

John

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Hi John

Thanks for your reply. I gues I thougt wrong, that only the resolution is nessacery for the number of DSI Lanes…

I will write you an E-Mail. Maybe we can solve this problem there.

Christoph