UART0 with UART_ASYNC_API not working after migrating from SDK2.6.0 to 2.9.0

[Dvd]

Hello,

currently I'm migrating a project from connect SDK 2.6.0 to 2.9.0. After some changes according to the migration guides the project builds fine and also runs. 

As hardware I am using a Nordic Nrf9160DK Revision 1.0.1.

For 2.6.0 everything worked fine but for 2.9.0 UART0 is not working at all. I use the UART0 interface to communicate with another MCU and disabled all the logging features.

I was looking at my prj.conf and saw some issues with the configuration for "CONFIG_UART_ASYNC_API" which stated that there are some missing dependencies "SERIAL_SUPPORT_ASYNC && SERIAL". In this case SERIAL is y and SERIAL_SUPPORT_ASYNC is not active.

Also activating "UART_NRFX" is not possible because the dependency "DT_HAS_NORDIC_NRF_UARTE_ENABLED=n". If I got this right, the dependency is automatically set if UARTE is enabled via device tree. I looked up both zephyr.config files from the build directory and saw that from 2.6.0 to 2.9.0 literally everything changed. For 2.6.0 I see that there are several configurations like "CONFIG_DT_HAS_NORDIC_NRF_UARTE_ENABLED=y" but for 2.9.0 there is not configuration with DT_HAS at all.

What am I missing or what could be the problem ?

[Kazi Afroza Sultana]

Hello,

I was looking at my prj.conf and saw some issues with the configuration for "CONFIG_UART_ASYNC_API" which stated that there are some missing dependencies "SERIAL_SUPPORT_ASYNC && SERIAL". In this case SERIAL is y and SERIAL_SUPPORT_ASYNC is not active

You may need to enable it (CONFIG_SERIAL_SUPPORT_ASYNC) in the prj.conf file.

Try adding all of these

CONFIG_SERIAL_SUPPORT_ASYNC=y

CONFIG_SERIAL=y

CONFIG_UART_ASYNC_API=y

The default pins for UART0 are  P0.26-P0.29. Are these set properly on your application?

Also activating "UART_NRFX" is not possible because the dependency "DT_HAS_NORDIC_NRF_UARTE_ENABLED=n"

Because this ''DT_HAS_NORDIC_UARTE__ENABLED=n'' indicates UARTE is not enabled in the device tree. Try enabling this 

CONFIG_NRFX_UARTE0=y in the prj.conf file.