gpiote interrupt resolution

Question

Can NRF52 gpiote detects pulse width nearly 250ns? We use a AFE sensor that notifies MCU it's data by sending a low to high pulse. The pulse width is about 250ns which is very small, I set the gpio triggering interrupt from low to high,but NRF52 can't run into the interrupt?

MartinBL · Accepted Answer

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.

gpiote interrupt resolution

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