Enter in SYSTEM ON doest not work

[Louis Hatte]

Hello everyone,

I'm using the nrf52840 Dev Kit (PCA10056 1.1.0 2019.19 683465548)

SDK version: 15.3

OS: Fedora

I work on a custom board and try to put it in SYSTEM ON mode like so:

int main(void)
{
    log_init();
    NRF_LOG_INFO("App start\n");
    NRF_LOG_FLUSH();

    power_management_init();
    for (;;) {
        nrf_pwr_mgmt_run();
    }
}

When I measure my consommation with OTII I get 4 mA instead of 1.5 uA according to this link (Debugging: Section 4).

Any ideas?

Regards,

Louis

[Simonr]

Hi Louis

The culprits of current consumption in the pwr_mgmt example are these functions:

APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
NRF_LOG_DEFAULT_BACKENDS_INIT();

NRF_LOG_INFO("Power Management example");

Logging does use power, as it initializes a few peripherals, I.E. UART or RTT depending on which one you use for logging. You can check by "un-commenting" these three lines from your main, and you'll see the 570uA draw again.

Best regards,

Simon