Device Power Consumption and Peripheral Usage

RE: Device Power Consumption and Peripheral Usage

Hung Bui — Wed, 08 Nov 2023 10:32:14 GMT

Hi Mayank,
It seems that the UART peripheral was not turned off correctly. HFCLK might be kept running by the UART peripheral.

Have you tried to test with our system_off sample (zephyr\samples/boards/nrf/system_off)?

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/samples/boards/nrf/system_off/README.html

Please try measuring the current consumption with this sample. In one of the step it will turn UART off and go to sleep mode.

RE: Device Power Consumption and Peripheral Usage

mayanktiwari — Tue, 07 Nov 2023 21:11:38 GMT

For QSPI issue cheking this :

https://github.com/zephyrproject-rtos/zephyr/pull/64782/commits/4c41e6c6dac0213eb58abafbfb4bf12a26c20595

RE: Device Power Consumption and Peripheral Usage

mayanktiwari — Tue, 07 Nov 2023 20:52:25 GMT

Hi Hung Bui,

I have the same device running in the field with NRF 17.1 SDK, and with this setup, I'm getting a current draw of 32 to 36 uA. I performed the same test with NCS idle mode, and the current draw is 56uA to 58 uA.

After performing UART operations: In NRF 17 SDK, after uninitiating UART, the current draw is 32 to 36 uA.

In NRF NCS, it's showing 320 to 280 uA, and it's not going down to 56uA to 58 uA.

When I check the UART, after disabling RX, it is disabled, but TX is still active and not disabled.

Another 10 uA is consumed by the QSPI Flash, out of the total 56uA.Additionally, after putting the QSPI Flash into deep sleep, the current draw is reduced to 46uA. However, there's an issue where the flash is not waking up from deep sleep.

RE: Device Power Consumption and Peripheral Usage

Hung Bui — Fri, 20 Oct 2023 11:25:21 GMT

Hi Mayank,

Could you please clarify this:

[quote user="mayanktiwari"]I'm still experiencing high current consumption of around 50uA on the UART side.[/quote]

Are you measuring 50uA current consumption on the NRF52840 after you disable UART ? I am not sure I understand what you meant by "on the UART side" .

20mA and 18mA is still way too high power consumption. I think there must be something else going wrong or you are measuring something else not just the nRF52840.

Could you please try testing with the system_off sample (\zephyr\samples\boards\nrf\system_off) ? In the sample there are several stages of low power and one will be with and without UART turn off.

Please try to compare the current consumption with what you have in your application. Also you should use a nRF52840 Dev Kit as a reference as well.

RE: Device Power Consumption and Peripheral Usage

mayanktiwari — Fri, 20 Oct 2023 04:14:48 GMT

Hi,

Thank you for your valuable suggestions. I've been working on reducing the current consumption, and I've made some progress, but I'm still facing high current consumption on the UART side.

I've already used the following code to suspend QSPI:`

pm_device_action_run(uart, PM_DEVICE_ACTION_SUSPEND);

While this has reduced the current consumption from 20mA to 18mA, I'm still looking to further optimize the UART section. Here's how I'm uninitializing the UART:

void uart_uninit(void)

{

pm_device_action_run(uart,PM_DEVICE_ACTION_SUSPEND);

if (uartInit) {

// Disable UART reception

uart_rx_disable(uart);

// Disable UART transmission (TX side)

uart_tx_abort(uart);

// Unregister the UART callback

uart_callback_set(uart, NULL, NULL);

// Reset the initialization flag

uartInit = 0;

}

However, even after running this code, I'm still experiencing high current consumption of around 50uA on the UART side. I'm also looking for a similar solution to uninitialize the I2C section.

If you have any further suggestions or insights on how to effectively uninitialize the UART and reduce the current consumption, please let me know. Your assistance is greatly appreciated.

Thank you.

RE: Device Power Consumption and Peripheral Usage

Hung Bui — Thu, 19 Oct 2023 14:10:55 GMT

Hi Mayank,

20mA is pretty high current consumption. In fact you only get there if you continuously transmitting data on the radio without using DCDC. And I guess it's not the case with your application.

Did you use the Power Profiler to measure the current consumption ?
The current consumption of 20mA was only the nRF52840 or it's also other components on the board ?
My suggestion is to try testing with some simple BLE application for example \nrf\samples\bluetooth\peripheral_lbs (use the prj_minimal.conf to config) should show the idle current of a few uA and the average current of a dozen uA.

You can also try to reduce the current consumption by turn off logging, turn off some of the peripheral. You should see a idle current of a few uA when the CPU is not running and no other peripheral is working.