MCU wakeup from sleep by a timer

RE: MCU wakeup from sleep by a timer

enkavak — Fri, 07 Sep 2018 12:37:42 GMT

No, I does not work.

RE: MCU wakeup from sleep by a timer

haakonsh — Fri, 07 Sep 2018 12:29:00 GMT

Turn off the RTC tick event and interrupt, then read out the content of the register again if it still does not work.

RE: MCU wakeup from sleep by a timer

enkavak — Fri, 07 Sep 2018 12:21:48 GMT

100.000 was an old trial number. even if I write 8 as the value, MCU never wakes up.

RE: MCU wakeup from sleep by a timer

haakonsh — Fri, 07 Sep 2018 11:53:16 GMT

With a prescaler value of 4095dec you will get an RTC frequency of 8Hz (32768Hz / PRESCALER + 1), and with a compare value of 100 000dec you will not trigger an event until 3,5 hours (100 000 ticks/ 8Hz * 60s * 60m) have passed...

RE: MCU wakeup from sleep by a timer

enkavak — Fri, 07 Sep 2018 11:22:23 GMT

When it is running

When It goes to sleep

RE: MCU wakeup from sleep by a timer

haakonsh — Fri, 07 Sep 2018 11:15:03 GMT

I need the content of the RTC2's registers...

RE: MCU wakeup from sleep by a timer

enkavak — Thu, 06 Sep 2018 13:19:08 GMT

yes, enabled and started.

RE: MCU wakeup from sleep by a timer

haakonsh — Thu, 06 Sep 2018 12:33:46 GMT

What is the state of the RTC2's register after you've configured, enabled, and started it?

RE: MCU wakeup from sleep by a timer

enkavak — Thu, 06 Sep 2018 10:15:58 GMT

actually LED is blinking When the MCU is active. there is no wakeup event occurs When the MCU goes into sleep mode.

RE: MCU wakeup from sleep by a timer

haakonsh — Thu, 06 Sep 2018 09:32:27 GMT

What is the state of the RTC2's register after you've configured, enabled, and started it?

RE: MCU wakeup from sleep by a timer

enkavak — Thu, 06 Sep 2018 08:54:31 GMT

OK, I used the RTC2. However, MCU never wakes up from sleep mode.

RE: MCU wakeup from sleep by a timer

haakonsh — Thu, 06 Sep 2018 08:40:29 GMT

RTC0 is used by the SoftDevice, RTC1 is used by the app_timer, I suggest you use RTC2 as the RTC instance.

RE: MCU wakeup from sleep by a timer

enkavak — Thu, 06 Sep 2018 07:54:18 GMT

When I do not use the below code into mine softdevice code, the code crashes at the line "ble_stack_init();"

static void rtc_handler(nrf_drv_rtc_int_type_t int_type)
{
    if (int_type == NRF_DRV_RTC_INT_COMPARE0)
    {
        nrf_gpio_pin_toggle(COMPARE_EVENT_OUTPUT);
    }
    else if (int_type == NRF_DRV_RTC_INT_TICK)
    {
        nrf_gpio_pin_toggle(TICK_EVENT_OUTPUT);
    }
}

/** @brief Function configuring gpio for pin toggling.
 */
static void leds_config(void)
{
    bsp_board_init(BSP_INIT_LEDS);
}

/** @brief Function starting the internal LFCLK XTAL oscillator.
 */
static void lfclk_config(void)
{
    ret_code_t err_code = nrf_drv_clock_init();
    APP_ERROR_CHECK(err_code);

    nrf_drv_clock_lfclk_request(NULL);
}

/** @brief Function initialization and configuration of RTC driver instance.
 */
static void rtc_config(void)
{
    uint32_t err_code;

    //Initialize RTC instance
    nrf_drv_rtc_config_t config = NRF_DRV_RTC_DEFAULT_CONFIG;
    config.prescaler = 4095;
    err_code = nrf_drv_rtc_init(&rtc, &config, rtc_handler);
    APP_ERROR_CHECK(err_code);

    //Enable tick event & interrupt
    nrf_drv_rtc_tick_enable(&rtc,true);

    //Set compare channel to trigger interrupt after COMPARE_COUNTERTIME seconds
    err_code = nrf_drv_rtc_cc_set(&rtc,0,COMPARE_COUNTERTIME * 8,true);
    APP_ERROR_CHECK(err_code);

    //Power on RTC instance
    nrf_drv_rtc_enable(&rtc);
}

RE: MCU wakeup from sleep by a timer

haakonsh — Wed, 05 Sep 2018 14:42:55 GMT

Any interrupt will wake the CPU.

"I have external xtal. Do I need to use "lfclk"?"
- Well, yes for the RTC you ned a LF clock source. If you've got a 32kHz crystal you can use the LFXO as the source. .

RE: MCU wakeup from sleep by a timer

enkavak — Wed, 05 Sep 2018 14:12:37 GMT

will this awake the MCU from sleep mode?

I have external xtal. Do I need to use "lfclk"?

RE: MCU wakeup from sleep by a timer

haakonsh — Wed, 05 Sep 2018 14:00:35 GMT

You can use RTC1-2. You can also use the Timer library (app_timer), see also Application Timer API docs.

RE: MCU wakeup from sleep by a timer

enkavak — Wed, 05 Sep 2018 13:55:08 GMT

Can I use it with the softdevice?

I have external xtal. Do I need to use "lfclk"?

In addition, does the resolution is second? I need resolution in milliseconds

RE: MCU wakeup from sleep by a timer

haakonsh — Wed, 05 Sep 2018 13:46:56 GMT

You'll want to use the RTC — Real-time counter. See the Real Time Counter Example and RTC API documentation.