nrf52810 SAADC + interrupt without HAL

[jca]

Please, give me an advice. I need to measure the supply voltage and trigger an interrupt after the measurement. An END interrupt is triggered only once. It must be without libraries, just by writing to NRF_SAADC->....

[haakonsh]

An END interrupt is triggered only once.

 Have you remembered to clear it after it has fired? 

[jca]

I start the measurement by software.

In interrupt the flag is cleared.:

void SAADC_IRQHandler(void)
{
    if(NRF_SAADC->EVENTS_END > 0)
    {
        NRF_SAADC->EVENTS_END = 0;

[haakonsh]

Try to use nrf_saadc_event_clear instead of NRF_SAADC->EVENTS_END = 0;

[jca]

It doesn't work. I have a project where bluetooth is used and due to the size of the softdevice, all logs must be turned off and libraries must not be used.

[haakonsh]

jca said:

libraries must not be used

 You need to use the HAL in order to operate the nRF52 safely, for instance: 

__STATIC_INLINE void nrf_saadc_event_clear(nrf_saadc_event_t event)
{
    *((volatile uint32_t *)((uint8_t *)NRF_SAADC + (uint32_t)event)) = 0x0UL;
#if __CORTEX_M == 0x04
    volatile uint32_t dummy = *((volatile uint32_t *)((uint8_t *)NRF_SAADC + (uint32_t)event));
    (void)dummy;
#endif
}

That dummy read is necessary, see Migrating from the nRF51 Series to the nRF52 Series -> Functional changes.