NRF_LOG_UART and APP_UART on nRF52840 SDK 17

[Nhuan]

Hi everyone,

How can I use both NRF_LOG_UART and APP_UART on nRF52840 (SDK 17) ?

Thank you

[Nhuan]

Now, I can LOG by UART. But, when I tried adding APP_UART into my project, I got a Fatal Error after APP_UART_FIFO_INIT() function and System Reset

In my sdk_config.h file, I added:

#define APP_UART_ENABLED 1
#define APP_UART_DRIVER_INSTANCE 1
#define APP_FIFO_ENABLED 1

 

and enabled:

#define UART1_ENABLED 1

What am I missing ?

[Amanda Hsieh]

Hi, 

Please refer to the sdk_config.h of UART Example and modify as the following:

#define APP_UART_ENABLED 1
#define APP_UART_DRIVER_INSTANCE 0
#define APP_FIFO_ENABLED 1
#define UART0_ENABLED 1
#define UART1_ENABLED 0

-Amanda H.

[Nhuan]

Hi Amanda,

I have already followed your recommended configuration, but I still got the Error 8:  NRF_ERROR_INVALID_STATE after APP_UART_FIFO_INIT() function

[Amanda Hsieh]

Do you have the NRF Logger module initialized? If this is set to use UART, you will not be able to initialize the UART module, and APP_UART_FIFO_INIT will return error code 0x08 (NRF_ERROR_INVALID_STATE).

-Amanda H.

[Nhuan]

But, I would like to use both NRF LOG UART and APP UART.

Is it possible?

[Amanda Hsieh]

Hi, 

Yes, on nRF52840 you can use the second UARTE instance (1)  for app_uart by changing APP_UART_DRIVER_INSTANCE

NRF_LOG UART backend is hardcoded to use instance 0. 

-Amanda H.