XIAO NRF52840 Plus - Sleep

Products & Technology XIAO
1

Are there any example programs for the XIAO NRF52840 Plus that demonstrate the sleep and wakeup possibilities for the board ?

Internal RTC sleep wakeup and external GPIO pin wakeup from deep sleep are my particular interests.

What are the typical battery sleep currents of the XIAO NRF52840 Plus ?

Note: I am only interested in information for the SEEED XIAO NRF52840 Plus board.

2

Hi there,

So, you do understand they are they same with just more I/O pins brought out to the open access. Power and Silicon is the same. Those pins were always there.

they are the same…

There may be some additional abilities to shut off some IO power group sections but nothing out of the ordinary.
From the level of experience you have I would suggest to start with the plethora of threads on the topic for the Xiao Nrf52840 without the plus, or even Sense because those are easy to understand and all have code and compiler output. besides it’s the same Apple to Apple so not to worry there.
The peripherals are just that. (IMU, MIC, LED’s)

Typical battery Sleep currents are in the threads by @msfujino
get a good handle on the baseline required and any items you want to add sensor wise you already know the impact of.
then jump to the Digikey Battery life calculator , which you will see in those threads also to pick the best battery for your power requirements. Not rocket science but a process.

HTH
GL :slight_smile: PJ :v:

Click that search Glass up there :point_up_2: I have a demo on both Sleep and wakeup’s with double-taps , a button or a timer it’s all there.
look at ALL of the @msfujino threads if you want to truly know the finer points and nuance to doing it right , things like shutting down items in order and setting IO states before doing so , etc.

If you just want examples there’s plenty. :+1: it’s the same processes and results.
one example…
code , output and a video… :sunglasses:

Xiao nRF52840 Sense IMU Parked demo With SLEEP Interrupt button

3

Thanks for that.

The key line in that application, that imposes the sleep, appears to be;

NRF_POWER->SYSTEMOFF = 1;

On my NRF52840 plus that yields a sleep current of 1.75mA. A NRF52840 ProMico board with the same code has a sleep current of 0.19mA.

Can the sleep current be reduced further ?

I note that for the NRF52840 SEEED advertise a ‘Standby power consumption: <5μA’ which is a long way from 1.75mA.

4

Hi there,

Yes, that is one of about 4 that are needed to get the numbers.
I can get 2-3uA. sleep on my device. The info is there on how it is achieved with code, you’ll have to read those and use what “Your” app requires. The Published Numbers are verified in there with code and results.
We are Glad to “TEACH” a man to fish here. :grin: :+1:

It’s a well worn Path you are on, so no surprises are ahead.

HTH
GL :slight_smile: PJ :v:

Try here :slight_smile: Sleep Current of XIAO nRF52840, Deep Sleep vs. Light Sleep - #7 by Devarshi_Bohra

deep sleep

ppk-Low_power_down
ppk-Low_power_down1920×1105 138 KB

and Light sleep 29’ish uA.
ppk-2uA_semiphore_do_work
ppk-2uA_semiphore_do_work2839×1545 133 KB

here is another…

5

The program works but ‘Deep Sleep’ is 4mA.

Will try the second one.

6

Hi there,

What Program? I don’t see any code?
You obviously missed something :face_with_hand_over_mouth:
Is the serial port still connected , did you power off the Flash? is the IMU on? (if it’s a Sense) Which BSP is in use? Too many omissions from the info to offer any further Guidance.

Post the code.
We can look.

GL :slight_smile: PJ :v:

7

The code I was using was what you linked to just above.

However, problem solved, I had the battery, where I was measuring current, connected to the ‘wrong’ place, as in the VIN pin on by the USB connector.

When connected to the pads underneath the PCB the sleep current is circa 12.7uA, which is low enough …

Thanks for your time.