I need DMA support for UART Communication protocal

[Goudam]

HI ,

I need dma support for the uart protocol but I can't seem to locate any examples of it being used with an uart. Can anyone give support on this?

regards ,

Goudam

[Jørgen Holmefjord]

Hi,

Which SDK are you using? Most of the UART examples we have use EasyDMA, but not all use it in an efficient way for receive operations.

For nRF Connect SDK, I would recommend you to look at the example from lession 5 in Nordic Developer Academy: nRF Connect SDK Fundamentals course, or this sample.

For nRF5 SDK, the libUARTE example is the recommended example for UART with EasyDMA.

Best regards,
Jørgen

[Jørgen Holmefjord]

Goudam said:

I'm using this example: github.com/.../main.c but I'm getting an ENOSYS error.

Where/when do you get this error? Have you made any modifications to the sample/configuration?

Goudam said:

I'm using a xiao ble board with a nrf52840 controller.

To enable EasyDMA (UARTE), you should also add the following to your board DTS or overlay file for the uart0/uart1 devices:

compatible = "nordic,nrf-uarte";

[Goudam]

Jørgen Holmefjord said:

Have you made any modifications to the sample/configuration?

I didn't modify anything in the code. In Board DTS itself NRF_UARTE enable 

I am noted one more thing CONFIG_UART_INTERRUPT_DRIVEN was enabled by default it makes any issue with ASYNC uart . If its a error means how to disable the CONFIG_UART_INTERRUPT_DRIVEN ?

I am try to disable that in prj.conf file by adding

CONFIG_UART_INTERRUPT_DRIVEN=n

[Jørgen Holmefjord]

You can only set a callback if the UART driver is configured in async mode, otherwise the function will return an error.

Try adding "CONFIG_UART_ASYNC_API=y" to your prj.conf.

[Goudam]

Jørgen Holmefjord said:

Try adding "CONFIG_UART_ASYNC_API=y" to your prj.conf.

Already this one is added in prj.conf file.

 I found the issue in the driver code, where the macro UARTE_ANY_ASYNC was not enabled, so that user space API uart_callback_set(uart, uart_cb, NULL) will not able to set the callback. I also checked with the nrf52840dk board, which has the same code and has the macro UARTE_ANY_ASYNC enabled, but the xiao_ble board does not enabled.

[Jørgen Holmefjord]

The UARTE_ANY_ASYNC symbol depends on the CONFIG_UART_x_ASYNC Kconfigs.

[Goudam]

Jørgen Holmefjord said:

CONFIG_UART_x_ASYNC

How to enable this macro because if i enable this in prj.conf file i got some errors . In windows how to use west build commands for change kconfig file

error: UART_0_NRF_UARTE (defined at drivers/serial/Kconfig.nrfx:38) is assigned in a configuration
file, but is not directly user-configurable (has no prompt). It gets its value indirectly from other
symbols. See http://docs.zephyrproject.org/latest/kconfig.html#CONFIG_UART_0_NRF_UARTE and/or look
up UART_0_NRF_UARTE in the menuconfig/guiconfig interface. The Application Development Primer,
Setting Configuration Values, and Kconfig - Tips and Best Practices sections of the manual might be
helpful too.

CMake Error at C:/ncs/v2.4.0/zephyr/cmake/modules/kconfig.cmake:339 (message):
  command failed with return code: 1
Call Stack (most recent call first):
  C:/ncs/v2.4.0/nrf/cmake/modules/kconfig.cmake:29 (include)
  C:/ncs/v2.4.0/zephyr/cmake/modules/zephyr_default.cmake:115 (include)
  C:/ncs/v2.4.0/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:66 (include)
  C:/ncs/v2.4.0/zephyr/share/zephyr-package/cmake/ZephyrConfig.cmake:97 (include_boilerplate)
  CMakeLists.txt:8 (find_package)


-- Configuring incomplete, errors occurred!
See also "D:/Projects/GE/Bluetooth_nRF2840/workspace/central_uart/build/CMakeFiles/CMakeOutput.log".
See also "D:/Projects/GE/Bluetooth_nRF2840/workspace/central_uart/build/CMakeFiles/CMakeError.log".
FAILED: build.ninja 
C:\ncs\toolchains\31f4403e35\opt\bin\cmake.exe --regenerate-during-build -SD:\Projects\GE\Bluetooth_nRF2840\workspace\central_uart -BD:\Projects\GE\Bluetooth_nRF2840\workspace\central_uart\build
ninja: error: rebuilding 'build.ninja': subcommand failed
FATAL ERROR: command exited with status 1: 'C:\ncs\toolchains\31f4403e35\opt\bin\cmake.EXE' --build 'd:\Projects\GE\Bluetooth_nRF2840\workspace\central_uart\build'

[Sigurd]

Hi,

Try:

CONFIG_UART_ASYNC_API=y

CONFIG_UART_0_INTERRUPT_DRIVEN=n
CONFIG_UART_0_ASYNC=y

[Goudam]

Hi sigurd

I am thanks for your support now its working for me while add the CONFIG_UART_0_INTERRUPT_DRIVEN=n in prj.conf file