Understanding Backends flushed warning - modified CLI example

Question

I have run up the CLI example to test as we will require some command line interaction and why reinvent the wheel?

I run up the example with USB enabled and UART disabled, I've changed the board type to include our I/O initialsation, otherwise the example is unmodified. This works as expected.

I modifed the counter output as we want to periodically report some values during production testing.

#define VERSION 101
volatile bool b1 = 0;
volatile bool b2 = 0;
volatile bool b3 = 1;
volatile uint16_t strain = 10;

static void timer_handle(void * p_context)
{
    UNUSED_PARAMETER(p_context);

    if (m_counter_active)
    {
        strain += 10;
        NRF_LOG_RAW_INFO("S,%d,%d,%d,%d,%d,\r\n", VERSION,b1,b2,b3,strain);
    }
}

This is the output

usb_cli:~$ counter start
S,101,0,0,1,20,
S,101,0,0,1,30,
S,101,0,0,1,40,
S,101,0,0,1,50,
S,101,0,0,1,60,
S,101,0,0,1,70,
S,101,0,0,1,80,
S,101,0,0,1,90,
[00:00:38.000,061] <warning> app: Backends flushed
[00:00:38.000,732] <warning> app: Backends flushed
S,101,0,0,1,100,
S,101,0,0,1,110,
S,101,0,0,1,120,
S,101,0,0,1,130,
S,101,0,0,1,140,
S,101,0,0,1,150,
S,101,0,0,1,160,
S,101,0,0,1,170,
[00:00:46.000,061] <warning> app: Backends flushed
[00:00:46.000,793] <warning> app: Backends flushed
S,101,0,0,1,180,
S,101,0,0,1,190,
S,101,0,0,1,200,
S,101,0,0,1,210,
S,101,0,0,1,220,
S,101,0,0,1,230,
S,101,0,0,1,240,
S,101,0,0,1,250,
[00:00:54.000,061] <warning> app: Backends flushed
[00:00:54.000,732] <warning> app: Backends flushed
S,101,0,0,1,260,
usb_cli:~$ counter stop

Digging around in the forum there are mentions of increasing NRF_LOG_BUFSIZE. This is set to 1024 in the example, the output is less than 150 bytes between warnings so I'm not sure why the warning is being generated.

Main loop is unchanged:

    while (true)
    {
        UNUSED_RETURN_VALUE(NRF_LOG_PROCESS());
#if CLI_OVER_USB_CDC_ACM && APP_USBD_CONFIG_EVENT_QUEUE_ENABLE
        while (app_usbd_event_queue_process())
        {
            /* Nothing to do */
        }
#endif
        cli_process();
    }

Board is using the MDBT50Q-1MV2 module (nRF52840), connected via USB. Running SES 4.52c and SDK 17.0.0.

Tom · Accepted Answer

Sorry Kenneth I must have missed the email notification for this one. 
 Regarding your suggestion, I'm not sure how I could call cli_process more frequently as all the while loop is dong is processing the log, USB events and processing the CLI. 
 In the end I reinvented the wheel as I couldn't work out how to solve the problem.

Understanding Backends flushed warning - modified CLI example

Top Replies