RE: gpiote interrupt resolution

kxJiang — Tue, 21 Nov 2017 08:37:36 GMT

Hi,Martin, Thanks for your reply. I added your code after my gpiote configuration code, then I found the problem.since nrf_drv_gpiote_init()was not called, nrf_drv_gpiote_in_init()returned on pin_in_use_by_gpiotechecking. It's my fault. Now it's working. Thanks again!

RE: gpiote interrupt resolution

MartinBL — Mon, 20 Nov 2017 15:52:11 GMT

Hi,

Have you looked at the pulses with an oscilloscope and made sure they go high enough to register as a logic high on the nRF52? The pulse must cross Vdd * 0.7.

I used an nRF52 DK and this code to measure pulses shorter than 250ns:

void GPIOTE_IRQHandler(void)
{
    nrf_gpio_pin_toggle(LED_1);
    NRF_GPIOTE->EVENTS_IN[0] = 0;
    NVIC_ClearPendingIRQ(GPIOTE_IRQn);
}

int main(void)
{
    LEDS_CONFIGURE(LEDS_MASK);
    LEDS_OFF(LEDS_MASK);
    nrf_gpio_cfg_input(BUTTON_1, NRF_GPIO_PIN_PULLUP);

    NRF_GPIOTE->INTENSET = 1;
    NRF_GPIOTE->CONFIG[0] = GPIOTE_CONFIG_MODE_Event << GPIOTE_CONFIG_MODE_Pos | 
             3 << GPIOTE_CONFIG_PSEL_Pos |
             GPIOTE_CONFIG_POLARITY_HiToLo << GPIOTE_CONFIG_POLARITY_Pos;
    
    NVIC_EnableIRQ(GPIOTE_IRQn);

    while (true)
    {
        __WFE();
    }
}

As long as you cross Vdd * 0.7, 250ns shouldn't be a problem.