Controller sleep mode and wake up

RE: Controller sleep mode and wake up

Kenneth — Wed, 16 Aug 2023 07:28:07 GMT

Please look at the /peripheral examples how it is used. Typically the 3 lines of code is executed in an infinite for(;;) loop in main, to ensure that the chip in system ON idle while waiting for interrrupts or events to wakeup the chip.

Kenneth

RE: Controller sleep mode and wake up

PMichael — Tue, 15 Aug 2023 13:29:58 GMT

Thank you. But can you please explain more detailed.

When I need to enter to sleep mode? shall I call this?

// Clear the event register.
__SEV();
__WFE();

What will happen when any interrupt? Instruction after __WFE(); will be performed?

RE: Controller sleep mode and wake up

Kenneth — Tue, 15 Aug 2023 13:13:50 GMT

The chip will enter system ON idle by calling sd_app_evt_wait() if you are using an application with a softdevice, or if you are not using a softdevice you can use:

// Wait for an event.
__WFE();

// Clear the event register.
__SEV();
__WFE();

Kenneth

RE: Controller sleep mode and wake up

PMichael — Wed, 09 Aug 2023 08:13:01 GMT

OFF mode is a very good solution, but what shall I do if I need to remain controller in ON mode to allow using of RTC? How can I send controller to sleep, but ON mode?

RE: Controller sleep mode and wake up

PMichael — Sat, 29 Jul 2023 10:36:16 GMT

Thank you

RE: Controller sleep mode and wake up

Vidar Berg — Mon, 24 Jul 2023 06:52:15 GMT

Yes, 'POWER' includes two general purpose retention registers (see GPREGRET).

RE: Controller sleep mode and wake up

PMichael — Sun, 23 Jul 2023 07:28:37 GMT

But regarding to all this there is additional question. Is in nRF52832 any general purpose register that I can init with any value before software reset and after software reset read correct value from this register. I need it to prevent OFF mode after firmware upgrade via BLE

RE: Controller sleep mode and wake up

PMichael — Sun, 23 Jul 2023 06:29:24 GMT

Thanks. It was a good idea. It works

RE: Controller sleep mode and wake up

Vidar Berg — Wed, 19 Jul 2023 07:35:41 GMT

The GPIO configurations, including the pull-up setting are retained in system OFF. Please try the code I posted and read the linked documentation.

RE: Controller sleep mode and wake up

PMichael — Wed, 19 Jul 2023 06:41:13 GMT

And additional question. What happen with internal pull up resistors in OFF mode? Will it work or I need to add external pull up resistor?

RE: Controller sleep mode and wake up

PMichael — Tue, 18 Jul 2023 13:21:24 GMT

This may be a good solution. But when device wake up from OFF mode, what happen? Reset with RESETREAS register bit RW OFF = 1 ? Is it correct?

RE: Controller sleep mode and wake up

Vidar Berg — Tue, 18 Jul 2023 13:03:54 GMT

You can have the device wake-up from a GPIO input event in System OFF mode. The implementation may look something like this:

#include "nrf_gpio.h"


void enter_system_off(void) 
{
    /* Configure wake-up pin */
    nrf_gpio_cfg_sense_input(BUTTON_1, GPIO_PIN_CNF_PULL_Pullup, NRF_GPIO_PIN_SENSE_LOW);

    NRF_POWER->SYSTEMOFF = 1;
    while(1);
}

/**@brief Application main function.
 */
int main(void)
{
    /* Enter system OFF mode after POR/BOR reset and wait for button press to trigger wake-up */
    if (NRF_POWER->RESETREAS == 0)
    {
        enter_system_off();
    }
    ...

RE: Controller sleep mode and wake up

PMichael — Tue, 18 Jul 2023 12:25:44 GMT

Because as I know in OFF mode chip cannot wake up from GPIO interrupt. Only reset. May be I am wrong. Please explain

RE: Controller sleep mode and wake up

Vidar Berg — Tue, 18 Jul 2023 12:22:22 GMT

Thanks for the clarification. But can you also explain why you don't want the chip to enter System OFF mode?

RE: Controller sleep mode and wake up

PMichael — Tue, 18 Jul 2023 12:17:21 GMT

Thank you. But function

static void power_manage(void)
{
uint32_t err_code = sd_app_evt_wait();
APP_ERROR_CHECK(err_code);
}

call softdevice function. I need to do it really in the beginning of start immediately after battery insertion. I need to set controller in sleep mode until button pressed. Pressing button shall switch the device on.

I cannot call any soft device functions.

How to do it without RTOS and without soft device functions?

Thank you

RE: Controller sleep mode and wake up

Vidar Berg — Tue, 18 Jul 2023 11:29:28 GMT

Hello,

Regarding the SCB register, please see my reply in this post: RE: nrf_pwr_mgmt_run impact of SCB_SCR_SLEEPDEEP_Msk . SCB is an ARM Cortex-specific register. Therefore, it is covered by the ARM documentation and not by our product specification.

[quote user=""]GPIO with interrupt. I am confused how to do it? Please explain how to set it in deep sleep?.[/quote]

You can call power_manage() from your main loop as we do in our examples. This will make the chip enter System ON mode when there is no work to do.

[quote user=""]Will controller perform next instruction after wake up and interrupt processing?[/quote]

The program will return to the code following your sleep function after processing the interrupt(s).

[quote user=""]In all examples I see code [/quote]

Isn't it only in the FreeRTOS example? Setting this bit is redundant anyway.

Best regards,

Vidar