Hi everyone
I am working with nRF52 (SD132). I am considering the ble_app_uart example and I'm trying to modify it by setting TIMER1 and TIMER2 peripherals to generate 2 different clocks HFCLK (6250 Hz) and LFCLK (1 Hz) so that they can be altered on-the-fly, allowing the user to change the clock frequencies using UART.
How could I do?
Thanks for your future answers.
Here what I wrote to set TIMER 1 and 2 peripherals:
/* TIMERS INITIALISATION **/
static void timers_init(void) { APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_OP_QUEUE_SIZE, false);
nrf_gpiote_task_configure(HFCLK_OUT_GPIOTE_CHAN, HFCLK_OUT, NRF_GPIOTE_POLARITY_TOGGLE, NRF_GPIOTE_INITIAL_VALUE_LOW);
nrf_gpiote_task_configure(LFCLK_OUT_GPIOTE_CHAN, LFCLK_OUT, NRF_GPIOTE_POLARITY_TOGGLE, NRF_GPIOTE_INITIAL_VALUE_LOW);
/* TIMER1 - HFCLK **/
NRF_TIMER1->TASKS_CLEAR = 1;
NRF_TIMER1->PRESCALER = HFCLK_TIMER_PRESCALER;
NRF_TIMER1->CC[0] = (uint32_t)((1/(float)(2HFCLK_OUT_FREQ)) (XTAL_FREQ >> HFCLK_TIMER_PRESCALER));
NRF_TIMER1->MODE = TIMER_MODE_MODE_Timer;
NRF_TIMER1->BITMODE = TIMER_BITMODE_BITMODE_16Bit;
NRF_TIMER1->SHORTS = (TIMER_SHORTS_COMPARE0_CLEAR_Enabled << TIMER_SHORTS_COMPARE0_CLEAR_Pos);
NRF_PPI->CH[HFCLK_OUT_PPI_CHAN].EEP = (uint32_t)&NRF_TIMER1->EVENTS_COMPARE[0];
NRF_PPI->CH[HFCLK_OUT_PPI_CHAN].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[HFCLK_OUT_GPIOTE_CHAN];
/* TIMER2 - LFCLK **/
SIMILAR CONFIGURATION OF THE TIMER1
/**/
// Enable PPI channels
NRF_PPI->CHEN = (PPI_CHEN_CH0_Enabled << PPI_CHEN_CH0_Pos) | (PPI_CHEN_CH1_Enabled << PPI_CHEN_CH1_Pos);
NRF_TIMER1->TASKS_START = 1;
NRF_TIMER2->TASKS_START = 1;
}
