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

How are you measuring your current consumption? I just tested the pwr_mgmt example myself and were able to measure ~570uA when the application was running, and ~0.3uA when I pressed button 1 to go to sleep mode using the PPK and an nRF52840DK. Additionally, when commenting out the same lines as you, I get a constant 2.3uA current using the same measurement setup. 

Best regards,

Simon

[Louis Hatte]

Hi Simonr

I returned into my application project code and:

1. Set DCDC mode in my main

2. Enable NRF_PWR_MGMT_CONFIG_USE_SCHEDULER in my SDK config

3. Fix an external peripheral problem ( which was drawning the 2 mA .... )

Now I measure ~580µA when I'm in SYSTEM ON just like you in your pwr_mgmt project.

I would like to go below 10µA, but i don't understand how the lines i have commented out in the pwr_mgmt project brought you from 570µA to 2.3µA. 
From my understanding, i have only commented Logs and AppScheduler which are not supposed to consume extra power.

Why do you get 2.3µA instead of 570µA when commenting lines I commented in pwr_mgmt example ?

Thanks