STM32F746-Disco Issue in using Ethernet and TouchGFX

[St32_User94]

Hello,

I am new to STM32F746-Disco and I was trying to develop an application starting from TouchGFX.

It went all good in developing a touchGFX app and use the generated .ioc and so on to configure a project but I've tried afterwards to configure the ethernet stack LWIP and so on but I was never able to communicate and ping the ethernet device.

I've tried on my local to run the ethernet example and I was able to properly ping the device but never been able to do it in the project configured with touchGFX.

The strange thing is that I can partially see some comunication such as ARP messages and so on but then the ethernet stack is not capable to reply to ping message. here a snapshot of the communication between my PC and the st board.

Does anyone might now what could be wrong in my configuration?
I've attached the .ioc

[STackPointer64]

Hello @St32_User94, and welcome to ST community!

Integrating both TouchGFX and LwIP in the same project requires careful memory management to avoid buffer overlaps. I noticed that in your LwIP configuration, you specified only 1600 bytes for MEM_SIZE, which is insufficient. Since you set LWIP_RAM_HEAP_POINTER to 0x20048000, you are likely allocating 16 KB. Therefore, you should update MEM_SIZE accordingly and reduce ETH_RX_BUFFER_CNT to 10 so it fits within the 16 KB.

Please try these changes and let me know your feedback.

Best regards,

[darenluie]

It’s likely a configuration mismatch between the TouchGFX project and the working LWIP example. TouchGFX often changes clock, MPU, or cache settings, which can break Ethernet replies. Check MPU regions, cache handling for LWIP buffers, and compare the clock tree with the example project—these are the usual causes when ARP works but ping fails.