ser_app_hal_hw_init() : using Internal RC instead of External Oscillator (with softdevice on)

[sam wagner]

I am looking into using Internal RC instead of External Oscillator (with softdevice on).

The function ser_app_hal_hw_init() uses Xtal clock source by default.

• Why does it not take clock_source as an argument, which is passed to sd_softdevice_enable() function? (see the code snippet below)

• Can you please indicate all the places where I need to mention Internal RC as the clock source during initialization to be sure that it is indeed used (with softdevice on)?

uint32_t sd_softdevice_enable(nrf_clock_lfclksrc_t clock_source, softdevice_assertion_handler_t assertion_handler) { uint32_t err_code;

err_code = ser_app_hal_hw_init();

: :

[Pertti Kasanen]

Partial answer below. This seems odd to me too, looks like the SDK currently only covers the case for external Low Frequency crystal?

I made a quick addition covering RC and Synth: In ser_softdevice_handler.c / sd_softdevice_enable() I changed the call to ser_app_hal_hw_init() as

if(clock_source == NRF_CLOCK_LFCLKSRC_SYNTH_250_PPM) {
    err_code = ser_app_hal_hw_init(CLOCK_LFCLKSRC_SRC_Synth);
} else {
    if(clock_source <= NRF_CLOCK_LFCLKSRC_XTAL_20_PPM) {
        err_code = ser_app_hal_hw_init(CLOCK_LFCLKSRC_SRC_Xtal);
    } else {
        err_code = ser_app_hal_hw_init(CLOCK_LFCLKSRC_SRC_RC);
    }
}

And then in ser_app_hal_nrf51.c changed the function see_app_hal_hw_init() to start as

uint32_t ser_app_hal_hw_init(uint32_t lfclksrc) {
    nrf_gpio_cfg_output(CONN_CHIP_RESET_PIN_NO);

    NRF_CLOCK->LFCLKSRC            = (lfclksrc << CLOCK_LFCLKSRC_SRC_Pos);

I'm just learning about the SDK myself there may be better ways to do this.

With this I can get the clock started with both RS and Synth. The SoftDevice seems to initialize. But starting BLE still fails with m_os_rsp_wait_handler() never returning.

Pertti