Source code to achieve 1.5uA standby current

[Sridhar Jonnavittula]

Hi all,

I wanted to see this below screen shot current number on nRF52840 DK

For that I changed peripheral/blinky example main() like this but I am seeing 14uA.

/* Configure board. */
//bsp_board_init(BSP_INIT_LEDS);

NRF_POWER->RAM[0].POWERCLR = 0xFFFF;
NRF_POWER->RAM[1].POWERCLR = 0xFFFF;
NRF_POWER->RAM[2].POWERCLR = 0xFFFF;
NRF_POWER->RAM[3].POWERCLR = 0xFFFF;
NRF_POWER->RAM[4].POWERCLR = 0xFFFF;
NRF_POWER->RAM[5].POWERCLR = 0xFFFF;
NRF_POWER->RAM[6].POWERCLR = 0xFFFF;
NRF_POWER->RAM[7].POWERCLR = 0xFFFF;
NRF_POWER->RAM[8].POWERCLR = 0xFFFF;

/* Toggle LEDs. */
while (true)
{
__WFE();
#if 0
for (int i = 0; i < LEDS_NUMBER; i++)
{
bsp_board_led_invert(i);
nrf_delay_ms(500);
}
#endif
}

Can anyone please provide me the source code to achieve that 1.5uA number?

Thanks

Sridhar

[Simonr]

Hi

I tested your code and was not able to see a 60µA average current draw like you are. Please make sure you're looking at the avg. current and not the max. current in the Power Profiler app. It should not be necessary to include the POWERCLR block in order to see this either. I see the same current draw with and without this added to the main loop. You're using a development kit and a PPK for these measurements, right?

Best regards,

Simon

[Sridhar Jonnavittula]

Actually we are using with other profiler. In PPK I see around 3uA.

1. Is 1.5uA is the value you have seen on your end?

2. Also I was trying to store some incremented value in NRF_POWER->GPREGRET in TICK event handler to store while in sleep. But it is not updating and I see same value every time in GPREGRET memory. Please tell the correct procedure.