current consumption with uarte0 and rtc2 in system on mode

RE: current consumption with uarte0 and rtc2 in system on mode

eleven-x_devteam — Thu, 19 Dec 2019 18:24:29 GMT

[quote userid="15146" url="~/f/nordic-q-a/53120/current-consumption-with-uarte0-and-rtc2-in-system-on-mode/217993"]Are you sure that RTC2 and RTC1 has the same configuration ?[/quote]

-> I found out RTC2 tick_latency was changed so that raised current consumption so much.

Thank you for your help.

RE: current consumption with uarte0 and rtc2 in system on mode

Sigurd — Fri, 01 Nov 2019 14:42:50 GMT

[quote userid="81663" url="~/f/nordic-q-a/53120/current-consumption-with-uarte0-and-rtc2-in-system-on-mode/217839"]We enabled RTC2 for os tick count and the sleep current is around 200uA with enabling rtc2 but when I change os tick reference to RTC1 ( even with 32K), using app timer and turn off RTC2, then the sleep current is around 5uA with enabling RTC1.[/quote]

Are you sure that RTC2 and RTC1 has the same configuration ?

What OS are you using ?

RE: current consumption with uarte0 and rtc2 in system on mode

eleven-x_devteam — Thu, 31 Oct 2019 19:05:12 GMT

Hi,

Thank you for the reply.

We were using 115200 and lower baud rate like 38400 can fix this but it's too slow.

So I've tried again to add more delay with another byte and some tweak at our os code then it was fixed.

Here is one more question about RTC.

I've checked again power consumption of RTC.

We enabled RTC2 for os tick count and the sleep current is around 200uA with enabling rtc2 but when I change os tick reference to RTC1 ( even with 32K), using app timer and turn off RTC2, then the sleep current is around 5uA with enabling RTC1.

I wonder if power consuming could be different between each channel of rtc

Thank you.

RE: current consumption with uarte0 and rtc2 in system on mode

Sigurd — Fri, 25 Oct 2019 12:21:02 GMT

[quote userid="81663" url="~/f/nordic-q-a/53120/current-consumption-with-uarte0-and-rtc2-in-system-on-mode/216457"]but when I turn on the system on mode, it seems the device are missing more than one byte and never recovered.[/quote]

Do you mean System OFF mode here?

[quote userid="81663" url="~/f/nordic-q-a/53120/current-consumption-with-uarte0-and-rtc2-in-system-on-mode/216457"]I've tried to send 0xff as wake-up command to give some delay[/quote]

Are you able to add some more delay? You could also try to lower the baudrate, and see if that helps.

RE: current consumption with uarte0 and rtc2 in system on mode

eleven-x_devteam — Wed, 23 Oct 2019 19:53:59 GMT

Hi,

Thank you for the answer.

About #1, as expected, it doesn't work after waking up without any code change so I've tried to send 0xff as wake-up command to give some delay and actually it worked without low power mode (system on), but when I turn on the system on mode, it seems the device are missing more than one byte and never recovered.

I am using the code below for enabling/disableing uart0 but nrf_serial_init() might be not fast enough to catch rx data even after 0xff.

So I've tried to use nrf_drv_uart_init instead but uart doesn't even start with this.

Do you any suggestion or any sample code for this?

--------------------------------------------------------

[uarte0 disble and set rx irq]

nrf_serial_uninit();

*(volatile uint32_t*)0x40002FFC = 0;

*(volatile uint32_t*)0x40002FFC;

*(volatile uint32_t*)0x40002FFC = 1;

if (!nrf_drv_gpiote_is_init())

{

nrf_drv_gpiote_init();

}

nrf_drv_gpiote_in_uninit(RX_PIN_NUMBER);

nrf_drv_gpiote_in_config_t config;

config.is_watcher = false;

config.hi_accuracy = false;

config.pull = NRF_GPIO_PIN_PULLUP;

config.sense = NRF_GPIOTE_POLARITY_HITOLO;

nrf_drv_gpiote_in_init(RX_PIN_NUMBER, &config, int_pin_fall_handler);

nrf_drv_gpiote_in_event_enable(RX_PIN_NUMBER, true);

[uarte0 enable]

nrf_serial_init();

RE: current consumption with uarte0 and rtc2 in system on mode

Dmitry — Thu, 10 Oct 2019 16:42:25 GMT

Hi,

#1 You can configure GPIO pin sense to wake by low level on RX pin. Start bit of the first byte will serve as wake-up signal, then you can route EVENTS_PORT to TASKS_STARTRX. I'm not sure that UART receiver will be in time to catch first byte, if not, you can send 0xff as wake-up command and ensure delay for one bit (or wait for '1' on RX) before starting UART peripheral to avoid synchronization issues.

#2 Maybe you can configure your OS to use SYSTICK timer? Then RTC2 could be run always at lowest frequency. Of course your way also makes sense.