ItsyBitsy NRF52840 power consumption

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amowry
 
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ItsyBitsy NRF52840 power consumption

Post by amowry »

I'm seeing that this board consumes about 7 mA running a "bare minimum" Arduino sketch. I was expecting it to be less based on what I've read on the Nordic site. I understand that the DotStar has some quiescent current in the <1 mA range, but other than desoldering that, are there suggestions for reducing the consumption of this board?

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mikeysklar
 
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Re: ItsyBitsy NRF52840 power consumption

Post by mikeysklar »

You can bypass the voltage regulator. Try pulling EN low and supplying 3v3 through the BAT pin.

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amowry
 
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Re: ItsyBitsy NRF52840 power consumption

Post by amowry »

Am I correct that delay() should put it into low power mode? I'm not seeing any change in consumption with an extended delay.

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mikeysklar
 
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Re: ItsyBitsy NRF52840 power consumption

Post by mikeysklar »

I do see a thread that mentions delay(100) 600uA. Had you come across this?

https://github.com/adafruit/Adafruit_nR ... issues/165

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amowry
 
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Re: ItsyBitsy NRF52840 power consumption

Post by amowry »

Thanks-- I had seen that, but it's not clear to me whether that functionality is implemented for this board (?). I thought I had read somewhere that delay() puts all the NRF52840 boards into sleep mode. Is there someone who could clarify that for me?
mikeysklar wrote: Thu Dec 01, 2022 5:57 pm I do see a thread that mentions delay(100) 600uA. Had you come across this?

https://github.com/adafruit/Adafruit_nR ... issues/165

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mikeysklar
 
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Re: ItsyBitsy NRF52840 power consumption

Post by mikeysklar »

There are some good threads in the Adafruit nRF52 repo related to super low power consumption for the nRF52840.

https://github.com/adafruit/Adafruit_nR ... /issues/51

The delay == sleep is true and mentioned here:
Throughput
Power Consumption

- delay = sleep thanks to freeRTOS tickless https://www.freertos.org/low-power-tickless-rtos.html
https://learn.adafruit.com/bluefruit-nr ... aq-3026483

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amowry
 
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Re: ItsyBitsy NRF52840 power consumption

Post by amowry »

Thanks, I've made some progress after reading those threads.

Has anyone here successfully enabled the internal DC/DC converter? The RayTac module has the necessary circuitry for it, and if I'm reading the Nordic documentation correctly, it reduces the CPU consumption by a whopping 3mA!

Or is the DC/DC enabled by default by Adafruit? I haven't found a reference for it?

From the Nordic documentation:
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DC-DC-consumption.jpg
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