app example “ble_app_hrs_s110_hci_pca10028 (nRF51 PCA10028)” on the 32 MHz crystal

[V.H.]

Hi Nordics,

I would like to run the app example “ble_app_hrs_s110_hci_pca10028 (nRF51 PCA10028)” on the 32 MHz crystal. Can anyone help to change the code to 32MHz base on the example?

V.H.

[Stian Røed Hafskjold]

You can start the HFCLK oscillator like this:

NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
NRF_CLOCK->TASKS_HFCLKSTART    = 1;
while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0){}
NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;

You can also synthesize LFCLK from HFCLK:

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

Note that even if you have a 32MHz crystal, the HFCLK will be scaled down to 16MHz