pwm with use of timer and ppi

Question

hi its not working as i want . y is that?

first step i try to toggle just with one cc that is the code below

with changing of NRF_TIMER2->CC[0] = 65536;nothing happend there is no difrence in changing it

y is that?

    nrf_gpio_cfg_output(PWM_OUTPUT_PIN_NUMBER);
    // Configure GPIOTE channel 0 to toggle the PWM pin state
    // @note Only one GPIOTE task can be connected to an output pin.
    nrf_gpiote_task_config(0, PWM_OUTPUT_PIN_NUMBER, \
                           NRF_GPIOTE_POLARITY_TOGGLE, NRF_GPIOTE_INITIAL_VALUE_LOW);

   // Configure PPI channel 0 to toggle PWM_OUTPUT_PIN on every TIMER2 COMPARE[0] match.
    NRF_PPI->CH[0].EEP = (uint32_t)&NRF_TIMER2->EVENTS_COMPARE[0];
    NRF_PPI->CH[0].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[0];


    // Enable PPI channels 0-2.
    NRF_PPI->CHEN = (PPI_CHEN_CH0_Enabled << PPI_CHEN_CH0_Pos);


    // Start 16 MHz crystal oscillator .
    NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
    NRF_CLOCK->TASKS_HFCLKSTART    = 1;

    // Wait for the external oscillator to start up.
    while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0) 
    {
        //Do nothing.
    }

    NRF_TIMER2->MODE      = TIMER_MODE_MODE_Timer;
    NRF_TIMER2->BITMODE   = TIMER_BITMODE_BITMODE_16Bit << TIMER_BITMODE_BITMODE_Pos;
    NRF_TIMER2->PRESCALER = TIMER_PRESCALERS;

    // Clears the timer, sets it to 0.
    NRF_TIMER2->TASKS_CLEAR = 1;

    // Load the initial values to TIMER2 CC registers.
    NRF_TIMER2->CC[0] = 65536;


    // Interrupt setup.
    NRF_TIMER2->INTENSET = (TIMER_INTENSET_COMPARE0_Enabled << TIMER_INTENSET_COMPARE0_Pos);


void TIMER2_IRQHandler(void)
{
    static bool cc0_turn = false; /**< Keeps track of which CC register to be used. */

    if ((NRF_TIMER2->EVENTS_COMPARE[0] != 0) && 
       ((NRF_TIMER2->INTENSET & TIMER_INTENSET_COMPARE0_Msk) != 0))
    {
			//NRF_TIMER2->TASKS_CLEAR = 1;
		}
}

Stefan Birnir Sverrisson · Accepted Answer

Hi 
 First question: Would you want to use app_pwm library instead of generating the PWM manually. The app_pwm internally uses TIMER+PPI+GPIOTE to generate the PWM. Valid from SDK 10.0.0. There is an example in the SDK.

pwm with use of timer and ppi

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