BL652 EVK Crystal Problem

[enkavak]

Hello,

      I am working with the BL652 EVK from LAIRD. The EVK has nRF52832 IC inside of the module. I downloaded the "nRF5_SDK_15.0.0_a53641a" and trying to use "ble_app_uart_pca10040_s132” application. This application is for nRF52832 with external crystal. The EVK that I use does not have an external crystal. I modified the code like below. However, I can not successfully run the code in the MCU. What could be the problem ? Can anyone help ?

nrf_clock_lf_cfg_t const clock_lf_cfg =

    {

        .source       = 0,

        .rc_ctiv      = 16,

        .rc_temp_ctiv = 2,

        .accuracy     = NRF_SDH_CLOCK_LF_ACCURACY

    };

[picben]

Hi,

The ble_app_uart example from the SDK calls the nrf_sdh_enable_request library function to enable the SoftDevice. This function gets the clock configuration from the sdk_config.h file. Have you tried changing the configuration of the clock directly in the sdk_config.h file ? A cleaner way, if you don't want to modify SDK files directly would be to add a app_config.h in the project and add the USE_APP_CONFIG preprocessor symbol in the compiler options. You then just re-define the options you want in the app_config.h file (in your case NRF_SDH_CLOCK_LF_SRC, NRF_SDH_CLOCK_LF_RC_CTIV, NRF_SDH_CLOCK_LF_RC_TEMP_CTIV and NRF_SDH_CLOCK_LF_ACCURACY). You must set the accuracy to 250ppm (or even 500ppm, according to nRF52832 errata #146) to get a stable BLE connection with the internal RC.

Another thing that you might want to check is the mapping of all I/O used by the ble_app_uart example on your board. I think the UART pins mapping is the same between the nRF52 DK and the BL652 EVK but I'm not so sure about the buttons and LEDs.

[enkavak]

Hello,

     I have changed the accuracy to 250ppm and even 500ppm, but nothing has changes. still I can not debug the code.

nrf_clock_lf_cfg_t const clock_lf_cfg =
{
.source = 0,
.rc_ctiv = 16,
.rc_temp_ctiv = 2,
.accuracy = 1
};

[picben]

Alright, it doesn't look like a clock configuration problem then, I am using the same configuration on a BL652 right now and it's working fine (it's on a custom PCB though, not on the evaluation kit).

I was going to suggest to make sure the SoftDevice is flashed along with the application but looking at your screenshot I think it's the case.

I suggest that you check how the buttons and LEDs pins are mapped on your Evaluation board (SIO_13 to SIO_20 of the BL652) and make sure nothing will go wrong if the application tries to access them maybe.

[enkavak]

Hello, picben.

        LED blinking is not the case since the flashed code is crashes somewhere. If there is another problem, then Why I can not debug the code, step by step?

       I think that I have the crystal configuration problem.

       Are you using the same SDK and application with me?

        I downloaded the "nRF5_SDK_15.0.0_a53641a" and trying to use "ble_app_uart_pca10040_s132” application.

      In addition to all, I am using segger embedded studio

Best Regards