GPIO wakeup from System ON sleep

RE: GPIO wakeup from System ON sleep

tyro01 — Thu, 23 Jun 2022 10:47:05 GMT

Hi Vidar,

I found a way to use System OFF sleep, which consumes less power than System ON sleep, so I decided to use your suggestion.

#define PIN_PWR_GOOD 4

void PWR_GOOD_wait_sysOFF(void)
{
    nrf_gpio_cfg_sense_input(PIN_PWR_GOOD, NRF_GPIO_PIN_PULLDOWN, NRF_GPIO_PIN_SENSE_HIGH);

    // Enter system OFF. After wakeup the chip will be reset, and code execution will run from the top 
    NRF_POWER->SYSTEMOFF = 1;
    
    for(;;){}
}

int main(void)
{
    nrf_gpio_cfg_input(PIN_PWR_GOOD, NRF_GPIO_PIN_PULLDOWN);
    
    if (nrf_gpio_pin_read(PIN_PWR_GOOD) == 0)
    {
        PWR_GOOD_wait_sysOFF();
    }
    ...
}

Thank you for your advice.

tyro

RE: GPIO wakeup from System ON sleep

tyro01 — Thu, 23 Jun 2022 03:00:12 GMT

Hi Vidar,

I can see your advice. I will try to return from the System ON sleep mode I originally planned. I will consider your proposal as well. I'm currently out. Please give me some time.

Thanks,

RE: GPIO wakeup from System ON sleep

Vidar Berg — Wed, 22 Jun 2022 12:10:41 GMT

Hi,

To wake-up from System ON mode (entered when you call __WFE) you need to configure the pin to trigger an interrupt. Here you have only configured the pin with sense enabled without configuration the GPIOTE interrupt. You can however use this configuration to wake the chip from System OFF mode. If this is what you want, then you can replace __WFE();__SEV();__WFE(); with NRF_POWER->SYSTEMOFF=1.

Best regards,

Vidar