STM32F769I-DISCO LCD RTOS LwIP : screen corrupted [solved]

[Joerg Wagner]

Posted on September 09, 2017 at 20:40

Hello.

Based on the HAL example >Applications>Display>LCD_PicturesFromSDCard I converted

this into a CubeMX (V1.7.0) project, which works fine. Adding FreeRTOS works as well.

But if I add LwIP (just adding) sometimes the image is not shown properly.

Parts of the image is corrupted on the screen.

Regardless if DHCP/static and memory settings for LwIP and FreeRTOS.

It does occur i.e. after every 6-20th image loading. There is no rule.

Why is it a problem to use LwIP in this case?

Thank you for every hint.

[Imen.D]

Posted on September 12, 2017 at 12:46

Hello,

Verify the stack and heap values of your project and I suggest that you take a look to the following resources about LWIP which can help you in your application:

• UM1718, paragraph 'B.3.6 LwIP' for the STM32CubeMX LwIP side.
• UM1713 “Developing applications on STM32Cube with LwIP TCP/IP stack“

Kind Regards

Imen

[Joerg Wagner · Accepted solution]

Posted on September 19, 2017 at 01:13

I found the reason:

Image files are processed via DMA and I also use DMA for sending data via UART.

Both streams are in the same DMA controller (#2) and this causes the collision.