Dear support,
I am using nRF52840DK (PCA10056) and nRF5 SDK version: nRF5_SDK_17.0.2_d674dde. I am trying to make all the prints in my application to be displayed properly via UART correctly. So, i am using the sample application as per the path: <SDK>/examples/peripheral/uart. Flashing is successful and when i connect the board using UART interface as shown in the image below and using minicom terminal on /dev/ttyACM0 to view the UART output.
The initial print which is present in the example main.c file is not printed at all. "printf("\r\nUART example started.\r\n");".
Also in the same main function and subsequent functions (which i have added myself for debugging purpose) invoked by this main function, if multiple printf( ) statements have been put continuously, then only a immediate printff( ) is displayed and subsequent printf( ) is displayed partially. Any more printf( ) statements present are not displayed at all.
example:
" printf("Hello World \r\n");
printf("Hello World \r\n");
printf("Hello World \r\n"); "
then the print on terminal is as below:
" Hello World
Hello W" < second printf is displayed partially and subsequent prints are not displayed at all. >
So, i tried the following options to solve this problem but was not working as expected.
1) added fflush(stdout) between subsequent printf( ), not working.
2) tried changing value for NRF_LOG_DEFERRED in config/sdk_config.h, not working
3) tried increasing value for UART_RX_BUF_SIZE and UART_TX_BUF_SIZE from 128 upto 8192, in config/sdk_config.h, not working
4) changed priority value for APP_UART_FIFO_INIT( ) from APP_IRQ_PRIORITY_LOWEST to APP_IRQ_PRIORITY_HIGHEST, in main.c not working
The following is working but not desired (adding information for adding clarity to problem statement):
1) Put a delay via nrf_delay_ms(500); between subsequent prints, then both the prints are displayed properly
" printf(" Hello World \r\n"); nrf_delay_ms(500); printf(" nRF52840DK board working \r\n"); "
2) Invoke app_uart_get( ); in between 2 consecutive printf( ), then both the prints are displayed properly.
" printf(" Hello World \r\n"); while(app_uart_get(&cr) != NRF_SUCCESS); printf(" nRF52840DK board working \r\n"); "
I am trying to adapt a custom embedded RTOS to be able run on nRF52840DK, so i cannot control the frequency and occurrence of printf( ) in the code. I want to get all printf() working as expected without loosing any prints, how to achieve that?
Thanks,
Nagesh
