UART communication disrupted when enabling LTDC display driver in Zephyr

[kreef19]

Hi there,

I'm currently working on a project using an stm32f429 discovery board with Zephyr v3.3.0 and zephyr-sdk v0.16.0. I've implemented UART Async for USART3 and connected it to an FTDI cable to display a simple message: "Hello world through the UART async driver".

However, when I enable the LTDC display driver in the project configuration with CONFIG_DISPLAY=y, the UART communication is disrupted. Instead of receiving the expected message, the UART RX and TX streams are filled with constant noise.

I'm new to Zephyr and I'm wondering if I may have made a mistake somewhere. Any suggestions for how to resolve this issue would be greatly appreciated.

I am using Zephyr V3.3.0 and the Zephyr sdk 0.16.0

The problem is caused by CONFIG_DISPLAY=y in prj.conf in the sources below.

uart_async.zip

Thank you!

NOTE: USART6 has the same issue

[kreef19]

So after some head scratching and discussions i have found the problem.
By checking MX cube it was quite clear what the problem was. So the solution was to use UART5