NRF52832: Disable all wakeup sources

[Rait]

Hi,

We would like to disable all wakeup sources before calling sys_poweroff. How to achieve this using Zephyr API? Pin configuration should remain as previously configured.

For background, we need to shut down the CPU in case of a low battery. CPU would only wake up from a power cycle (replace battery).

Cheers

[Charlie]

Hi Rait,

You can not disable wakeup sources of System OFF mode. It is the lowest power mode you can achieve(0.3 μA at 3 V) and designed with following wakeup sources:
1. The DETECT signal, optionally generated by the GPIO peripheral

2. The ANADETECT signal, optionally generated by the LPCOMP module

3. The SENSE signal, optionally generated by the NFC module to “wake-on-field”

4. A reset

There is no chance GPIO can survive power on reset according to specification. GPIO will do initialization after power reset any way, but you can store and load configurations via settings subsystem.

You can find more information from nRF52832 Product Specification (nordicsemi.com).

Best regards,

Charlie

[Rait]

Thanks for the reply.

GPIO config does not have to survive a reset. The goal is to disable wakeup from any pin configured as input with interrupt(buttons etc.) and also keep the outputs as previously set. LPCOMP and NFC are not used.

Hoping to find a solution that does not involve reconfiguring all individual input pins.

Cheers

[Charlie]

You can try to use GPIO configuration NRF_GPIO_PIN_NOSENSE to disable DETECT signal. This is the actual wake-up source from GPIO.

[Rait]

Can you please provide a code snippet?

[Charlie]

nrf_gpio_cfg(pin,

             NRF_GPIO_PIN_DIR_INPUT,

             NRF_GPIO_PIN_INPUT_DISCONNECT,

             pull,

             NRF_GPIO_PIN_S0S1,

             NRF_GPIO_PIN_NOSENSE);

[Rait]

Thanks. However, as mentioned I am looking for a solution using Zephyr API without the need of reconfiguring individual pins.

[Charlie]

This configuration is highly customized by nrf chips, so there is no general Zephyr API generated for this purpose.