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UART works only debug mode

Hi,

I am using own hardware board based on https://www.raytac.com/product/ins.php?index_id=24 module, it uses nRF52840.

I am facing an strange issue that UART is not working in normal mode but it is transferring a char when i add break point and run it.

If just keep in debug mode and run still it is not sending anything to uart transfer only when i add break point that too with single char put.

HI have taken uart example and removed the uart get byte part and kept only uart put byte part with default ascii char for every 500ms.

/**
 * @brief Function for main application entry.
 */
int main(void)
{
    uint32_t err_code;

   // bsp_board_init(BSP_INIT_LEDS);

	
    const app_uart_comm_params_t comm_params =
      {
          RX_PIN_NUMBER,
          TX_PIN_NUMBER,
          RTS_PIN_NUMBER,
          CTS_PIN_NUMBER,
          UART_HWFC,
          false,
#if defined (UART_PRESENT)
          NRF_UART_BAUDRATE_115200
#else
          NRF_UARTE_BAUDRATE_115200
#endif
      };

    APP_UART_FIFO_INIT(&comm_params,
                         UART_RX_BUF_SIZE,
                         UART_TX_BUF_SIZE,
                         uart_error_handle,
                         APP_IRQ_PRIORITY_LOWEST,
                         err_code);

    APP_ERROR_CHECK(err_code);

#ifndef ENABLE_LOOPBACK_TEST
    printf("\r\nUART example started.\r\n");

    while (true)
    {
        uint8_t cr;
        //while (app_uart_get(&cr) != NRF_SUCCESS);
			cr = 'A';
        while (app_uart_put(cr) != NRF_SUCCESS);
			LED0_Toggle();
        nrf_delay_ms(500);
    }
#else

    // This part of the example is just for testing the loopback .
    while (true)
    {
        uart_loopback_test();
    }
#endif
}

P0.00 and P0.01 are connected to external 32Khz crystal, I dont have way to verify the crystal generate clock or not. Even if external crystal failed to work i am expecting internal RC to work.

Please help me to understand how to enable the RC clock and soft device if required .

Or what could the root cause of the issue ?

I have attached uart example code with sdkconfig i am using it. Please help me with this.

SDK used: \nRF5_SDK_17.0.2_d674dde\examples\peripheral\uart

r2n_uart_test.zip

Parents

0 Simonr over 5 years ago

Can you provide the return of the UART callback function and debug log so we can get some more details as to what's going on here?

A common mistake in custom boards is that the 32.768kHz crystal is soldered on the wrong way (90 degrees off), so a malfunctioning 32kHz crystal may indeed be your problem.

Please try changing the following defines in your sdk_config.h file to enable the internal RC oscillator and the correct calibration interval.

// <h> Clock - SoftDevice clock configuration

//==========================================================
// <o> NRF_SDH_CLOCK_LF_SRC  - SoftDevice clock source.
 
// <0=> NRF_CLOCK_LF_SRC_RC 
// <1=> NRF_CLOCK_LF_SRC_XTAL 
// <2=> NRF_CLOCK_LF_SRC_SYNTH 

#ifndef NRF_SDH_CLOCK_LF_SRC
#define NRF_SDH_CLOCK_LF_SRC 0
#endif

// <o> NRF_SDH_CLOCK_LF_RC_CTIV - SoftDevice calibration timer interval. 
#ifndef NRF_SDH_CLOCK_LF_RC_CTIV
#define NRF_SDH_CLOCK_LF_RC_CTIV 16
#endif

// <o> NRF_SDH_CLOCK_LF_RC_TEMP_CTIV - SoftDevice calibration timer interval under constant temperature. 
// <i> How often (in number of calibration intervals) the RC oscillator shall be calibrated
// <i>  if the temperature has not changed.

#ifndef NRF_SDH_CLOCK_LF_RC_TEMP_CTIV
#define NRF_SDH_CLOCK_LF_RC_TEMP_CTIV 2
#endif

// <o> NRF_SDH_CLOCK_LF_ACCURACY  - External clock accuracy used in the LL to compute timing.
 
// <0=> NRF_CLOCK_LF_ACCURACY_250_PPM 
// <1=> NRF_CLOCK_LF_ACCURACY_500_PPM 
// <2=> NRF_CLOCK_LF_ACCURACY_150_PPM 
// <3=> NRF_CLOCK_LF_ACCURACY_100_PPM 
// <4=> NRF_CLOCK_LF_ACCURACY_75_PPM 
// <5=> NRF_CLOCK_LF_ACCURACY_50_PPM 
// <6=> NRF_CLOCK_LF_ACCURACY_30_PPM 
// <7=> NRF_CLOCK_LF_ACCURACY_20_PPM 
// <8=> NRF_CLOCK_LF_ACCURACY_10_PPM 
// <9=> NRF_CLOCK_LF_ACCURACY_5_PPM 
// <10=> NRF_CLOCK_LF_ACCURACY_2_PPM 
// <11=> NRF_CLOCK_LF_ACCURACY_1_PPM 

#ifndef NRF_SDH_CLOCK_LF_ACCURACY
#define NRF_SDH_CLOCK_LF_ACCURACY 1
#endif

Best regards,

Simon

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