Possible error in LCD configuration (wrong segment numbers)

[KDwor.17]

Hello

In glass LCD display configuration (for STM32L152RB in my case), for static display, in Cube we can see segment numbers SEG[0-31]. Meanwhile, SEG[31:28] are double numbered, also to SEG[43:40]. To use [31:28] designators there must be MUX_SEG bit in LCD_CR set.

After code generation MUX_SEG is still disabled (0). I found the line in MX_LCD_Init function:

hlcd.Init.MuxSegment = LCD_MUXSEGMENT_DISABLE;

And i can't find proper setting in Cube to enable this MUX, i has to do it manually after code generation.

This problem is misleading, because segments 31-28 are located in ROM[0] register, 43-40 in ROM[1] register. Cube shows numbers 31-28, we try to write ROM[0] register, what is not working, because this segments has numbers 43-30 and we should write other register (ROM[1]). And this is because of wrong MUX_SEG bit settings.

Could you check this somehow?

[Khouloud ZEMMELI]

Hello @KDwor.17​ 

You need to check the check-box "multiplex mode" to obtain : hlcd.Init.MuxSegment = LCD_MUXSEGMENT_ENABLE .

Please use the latest CubeMX version.

Thanks

Khouloud

[pototschnig]

Thx a lot, this saved me a lot of time! I'm using a 1/4 duty cycle glass with 32 segments and used this as workaround:

  for (int i = 0; i < 4; i++) {
    HAL_LCD_Write(&hlcd, i * 2, 0, lcdram[i]);
    HAL_LCD_Write(&hlcd, i * 2 + 1, 0, (lcdram[i] & 0xf0000000) >> 20);
  }
  HAL_LCD_UpdateDisplayRequest(&hlcd);

 I'm writing from my own shadow-registers the upper most 4 bits on the next register shifted by 20 bits, then it works with LCD_MUXSEGMENT_DISABLE.

But you are right, this is very confusing done.