Text and bitmap displayed, but line is not displayed

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    • Text and bitmap displayed, but line is not displayed

      I'm testing a new LCD with LTDC RGB interface from STM32L4R7.
      Until now I can show string (GUI_DispString()) and bmp (GUI_DrawBitmap()). So far so good.

      But it is not possible to display line, rectangle, circle and so on. It is very strange...
      Set pen size is on 10.

      Any idea?

      Thank you
    • New


      The project comes out of the fridge ...

      In addition to the line problem like in the previous post, I have another problem that I can not solve.
      I do not have an external RAM (screen is 800x480), so I have to use in 8 bit (grayscale or color). But the screen displays color that does not match. And I tried several GUICC_XX.

      When I look at the oscilloscope, it seems that all bits (24) are driven. Normally only MSBit in color channels should be driven...

      The code is in attachment.

      Thank you.
      • LCDConf.txt

        (30.34 kB, downloaded 2 times, last: )
    • New

      One more thing: In the STM32 RM it is said:

      "For LTDC outputs up to 24-bit (RGB888), if less than 8 bpp are used to output for example
      RGB565 or RGB666 to interface on 16- or 18-bit displays, the RGB display data lines must
      be connected to the MSB of the LCD-TFT controller RGB data lines. As an example, in the
      case of an LCD-TFT controller interfacing with a RGB565 16-bit display, the LCD display
      R[4:0], G[5:0] and B[4:0] data lines pins must be connected to LCD-TFT controller
      LCD_R[7:3], LCD_G[7:2] and LCD_B[7:3]."

      Then I remap like this
      STM32 R6 to LCD R0
      STM32 R7 to LCD R1
      STM32 G5 to LCD G0
      STM32 G6 to LCD G1
      STM32 G7 to LCD G2
      STM32 B5 to LCD B0
      STM32 B6 to LCD B1
      STM32 B7 to LCD B2

      But the result is less good.