nRF52832 does not wake up on event using __WFE

[eBrock]

nRF52832 doesn't seem to wake up when an event is generated. I confirmed that the RTC0 is active and the event is generated

upon COMPARE[0] match using the SES debugger. But nothing happens when the RTC0 generates the event. Sleep current is

about 3.5 uA. I can see the current going from about 5.7 mA down to 3.5 uA after 2s delay (following program code). I have read

in another post that the micro should wake up from an event firing, but that doesn't seem to be happening. I'm probably missing

something. Any help is greatly appreciated.

Nordic SDK 15.3.0

SES v4.22

#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include "nrf.h"
#include "nrf_delay.h"
#include "nrf_gpio.h"

#define LED_1          17


void hf_clock_start( void )
{
    // Start HFCLK and wait for it to start.
    NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
    NRF_CLOCK->TASKS_HFCLKSTART = 1;
    while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0);
    nrf_delay_ms(1);
}


void lf_clock_start( void )
{
    // Start LFCLK and wait for it to start.
    NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
    NRF_CLOCK->TASKS_LFCLKSTART = 1;
    while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0);
    nrf_delay_ms(1);
}


void gpio_init( void )
{
    nrf_gpio_cfg_output(LED_1);
    nrf_gpio_pin_write(LED_1, 0);

}


void rtc_init( void )
{
    NRF_RTC0->PRESCALER = 0x0;
    NRF_RTC0->CC[0] = 0x10001;
    NRF_RTC0->EVTEN = 0x10000;
    NRF_RTC0->TASKS_CLEAR = true;
    NRF_RTC0->TASKS_START = true;
    nrf_delay_ms(1);
}


void low_power_sleep( void )
{
    NRF_RTC0->TASKS_CLEAR = true;
    NRF_RTC0->EVENTS_COMPARE[0] = 0;
    __WFE();
}


int main(void)
{
    hf_clock_start();
    lf_clock_start();
    gpio_init();
    rtc_init();


    while (true)
    {
        nrf_delay_ms(2000);
        NRF_CLOCK->TASKS_HFCLKSTOP = true;
        nrf_gpio_pin_toggle(LED_1);
        low_power_sleep();
        hf_clock_start();
        nrf_gpio_pin_toggle(LED_1);
    }
}

[eBrock]

I changed to using __WFI as it seems to work best for my application.

Here is current code for the sleep functionality:

void RTC0_IRQHandler( void )
{
    NRF_RTC0->TASKS_CLEAR = true;
    NRF_RTC0->EVENTS_COMPARE[0] = 0;
}

void rtc_init( void )
{
    NRF_RTC0->PRESCALER = 0x0;
    NRF_RTC0->CC[0] = 0x10001;
    NRF_RTC0->TASKS_CLEAR = true;
    NRF_RTC0->TASKS_START = true;
    NVIC_EnableIRQ(RTC0_IRQn);
    nrf_delay_ms(1);
}

void low_power_sleep( void )
{
    NRF_RTC0->INTENSET = 0x10000;
    NRF_RTC0->TASKS_CLEAR = true;
    NRF_RTC0->EVENTS_COMPARE[0] = 0;
    __WFI();
    NRF_RTC0->INTENSET = 0x00000;
}