[nrf51][nrf52][low power] How to enter low power consumption when using RTX

1. Because RTX uses the RTC1 interrupt, it wakes up frequently and cannot enter the sleep state.

2. Idea: Before entering low power consumption, turn off the power of RTC1, and reconfigure RTC1 after waking up with a button.

pseudocode:

Before entering low power consumption

1. Turn off peripheral GPIO

        nrf_gpio_cfg_default(N);

2. Close the serial port

        NRF_UART0->ENABLE = 0;

        NRF_UART0->POWER = 0;

        app_uart_close();

3. Disable RTC1 interrupt

        __disable_irq();

        NVIC_DisableIRQ(RTC1_IRQn);

        NRF_RTC1->POWER = 0; //Stop RTC

        __enable_irq();

4. Set key interrupt

        KEY_IRQn_INIT();

        /*

        Content Examples

        NRF_GPIO->PIN_CNF[Config_Key1_PORT_PIN] |= (GPIO_PIN_CNF_SENSE_Low << GPIO_PIN_CNF_SENSE_Pos);

        NRF_GPIOTE->INTENSET = GPIOTE_INTENSET_PORT_Msk; //Enable interrupt

        NVIC_SetPriority(GPIOTE_IRQn, 1); //Set the interrupt priority to 1

        NVIC_EnableIRQ(GPIOTE_IRQn); //Enable general interrupt

        */

5. Go to sleep

        sd_app_evt_wait();

Key interrupt function:

void GPIOTE_IRQHandler(void) //GPIOTE interrupt service function

{

    unsigned int expected_time;

    if (NRF_GPIOTE->EVENTS_PORT != 0)

    {

        NRF_GPIOTE->EVENTS_PORT = 0; //Interrupt clear

        if (NRF_RTC1->POWER == 0)

        {

            NVIC_EnableIRQ(RTC1_IRQn);

            NRF_RTC1->POWER = 1; //Start RTC

            NRF_RTC1->EVENTS_TICK = 1; //Start counting

            NRF_RTC1->TASKS_START = 1; //Start counting

            NRF_RTC1->PRESCALER = 0x20; //Set clock reference 32768 0x20==32

        }

        if (nrf_gpio_pin_read(Config_Key5_PORT_PIN) == 0) //Check whether it is woken up by this button

        {

        }

    }

}