how can adjust to dozens of uA (with freertos)

RE: how can adjust to dozens of uA (with freertos)

Dave_couling — Wed, 08 May 2019 22:58:41 GMT

Remove the Idle hook

RE: how can adjust to dozens of uA (with freertos)

Susheel Nuguru — Thu, 06 Jul 2017 08:08:43 GMT

Thanks for that information labi.

RE: how can adjust to dozens of uA (with freertos)

labi — Sun, 02 Jul 2017 19:35:44 GMT

Turns out the Sparkfun NRF52 breakout board has a LDO regulator which was consuming extra current though I was supplying the output side of the LDO. Once I removed the LDO, the current draw is now around 70 uA! :)

RE: how can adjust to dozens of uA (with freertos)

labi — Sun, 02 Jul 2017 19:08:33 GMT

UPDATE: I ran the same firmware on the NRF52-DK and measured ~75uA current on P22. Looks like the Sparkfun NRF52 target may be leaking some extra current somewhere or there's some other issue. Will post here if I find anything. Thanks for your support!

RE: how can adjust to dozens of uA (with freertos)

labi — Sun, 02 Jul 2017 15:46:39 GMT

I just replaced port_cmsis_systick.c as decribed on the post. Current is still at ~800uA :(

I tried both softdevice 4.0.2 and 4.0.4 with the same result. Anything else I can try?

RE: how can adjust to dozens of uA (with freertos)

Susheel Nuguru — Sun, 02 Jul 2017 13:17:42 GMT

Hi labi,

I missed to see this thread is out of date. If you are using SDK 13, then you need to change only one file and it is shown here. I will update my answer.

RE: how can adjust to dozens of uA (with freertos)

labi — Sun, 02 Jul 2017 01:23:08 GMT

Hi Aryan,

Im looking into reducing power usage in my application as well, but havent had any luck reducing the current lower than around 800uA. Here's what I've done so far:

Downloaded SDK 13.0.0 / softdevice 4.0.2 - ble_app_hrs_freertos consumes about 8mA - NRF toolbox cannot connect to device - connection keep disconnecting
Set NRF_LOG_ENABLED to 0 in the same project - current went down to 800uA - NRF Toolbox can now connect reliably
Applied above fix provided by you - current is still at 800uA
Changed to Softdevice 4.0.4 - no change in current - Connection stays OK
Disabled Idle hook - no change in current - connection stays OK
Changed to Softdevice 5.0.0-3.alpha - Current went up to 6.5mA - NRF Toolbox cant connect to device any more

Any Ideas what Im doing wrong or how I can lower the current down to 100uA as documented here?

My hardware setup is NRF52-DK (used as a debugger) ---> Sparkfun NRF52 breakout board as target

I'm using armgcc compiler on Ubuntu Linux

All current measurements listed here are measured using a Fluke 87V True RMS Multimeter measuring current going into the target board, with NRF52-DK switched off.

Any help would be very much appreciated.

Thank You,

RE: how can adjust to dozens of uA (with freertos)

Susheel Nuguru — Fri, 03 Feb 2017 11:53:49 GMT

I have tested this myself and many other customers confirmed that now SDK FreeRTOS example takes about 100uA instead of 800uA after this fix.

RE: how can adjust to dozens of uA (with freertos)

Susheel Nuguru — Fri, 03 Feb 2017 11:39:59 GMT

updated(2 July 2017)

Use SDK 13 and replace the file given in this thread. It is best not to post files in many threads as we might loose track and forget to update the thread.

RE: how can adjust to dozens of uA (with freertos)

canan — Fri, 03 Feb 2017 01:45:46 GMT

The minimum system board is PCA10040 V0.9.0, ammeter in series with P22 (nRF current measurement), the freertos routine (ble_app_hrs_freertos) in SDK V13.0.0 is 800uA (1000ms broadcast interval);

RE: how can adjust to dozens of uA (with freertos)

Arnaud Nelissen — Thu, 26 Jan 2017 15:56:26 GMT

All the FreeRTOS examples I tried (from SDK 12 to 14 and associated softdevices) showed up a 800µA current consumption. I managed to get 30µA with a NON FreeRTOS example (ble_app_template). I can't see which peripheral is running, as the examples do not start one... I opened a case on MyPage.

Thank you for your help.

RE: how can adjust to dozens of uA (with freertos)

Arnaud Nelissen — Thu, 26 Jan 2017 12:45:19 GMT

I also face this problem (around 800µA of current consumption), using FreeRTOS example on my custom board design (SDK 12.0.2 Softdevice s132 3.1.0, nRF52832 QFAAB0).

I removed any advertised BLE service, disabled NRF LOG module, applied the diff @Aryan just provided, and the FPU irq handler fix without success. My freeRTOSConfig file features :

#define configUSE_TICKLESS_IDLE 1
#define configUSE_TICKLESS_IDLE_SIMPLE_DEBUG 1
...
#define configUSE_IDLE_HOOK 1
#define configUSE_TICK_HOOK 0

I also tried another example without FreeRTOS (ble_app_template), my current consuption is brought down to around 30µA.

I off course detach the debugger and power cycle the board before testing current consumption.

Do you have any idea what's going on ?

RE: how can adjust to dozens of uA (with freertos)

Susheel Nuguru — Wed, 25 Jan 2017 21:32:48 GMT

well if you have not configured the FreeRTOS to be in tickless idle mode, then it will consume more power because at the SDK default tick frequency, it will wake up the chip almost every millisecond. Use tickless idle as shown here

Built in tickless idle functionality is enabled by defining configUSE_TICKLESS_IDLE as 1 in FreeRTOSConfig.h

NOTE : there was a bug in tickless idle mode that made loose ticks.Apply the changes from my answer below in this case.

RE: how can adjust to dozens of uA (with freertos)

Roger Clark — Wed, 25 Jan 2017 08:36:53 GMT

Log is not enabled by default in that example, but I don't know if it uses the UART in some other way, probably not.

Did you power cycle the board after uploading

And what do you mean my "Minimum system board", do you mean custom design?

RE: how can adjust to dozens of uA (with freertos)

canan — Wed, 25 Jan 2017 07:01:24 GMT

That is the SDK routine, I only revised the broadcast interval, why SDK routines with freertos power so high?

RE: how can adjust to dozens of uA (with freertos)

Roger Clark — Wed, 25 Jan 2017 06:06:05 GMT

I presume you have ruled out things like the MCU being in debug mode and that the UART is not enabled etc ?