How to minimize the power consumption of QSPI flash on 52840DK?

[Anthony Yuan]

Hi,

I am running Homekit over Thread sample(NCS/Homekit tag v1.7.0 using MTD-SED conf) on my custom board and I found that the QSPI Flash (MX25R64, as same as the one use on 52840DK) consume >1mA.

And I tested the default Homekit multiprotocol sample application(MTD-SED) on 52840DK and have the same result (DK cut SB16/short SB18 and using PPK2 to measure current).

Is there any samples to show how to minimize the power consumption of QSPI flash on 52840DK?

I think zephyr/nrf driver should handle DPD status after each read/write of the flash, Is the Homekit multiprotocol sample do not set the Macronix flash into deepsleep mode?

Regards,

Anthony Yuan

[Anthony Yuan]

Hi Sigurd Hellesvik,

Thanks for your reply.

I checked the generated .config files for both application and mcuboot, now

# CONFIG_LOG is not set
# CONFIG_SERIAL is not set

And then I tested the same merged hex on 2 52840DKs:

DK1, cut SB16, short SB18 (use VDD_nRF instead of VDD_PER as the power source of the external memory)

DK2, short SB16, open SB18 (as default on DK, use VDD_PER as the power source of the external memory)

Both DKs are measured with PPK2 like this and switch the SW6 "nRF ONLY | DEFAULT" to "DEFAULT" on 52840DK

I think 52840 itself have proper current consumption but the external memory was not been set to DPD to save power.

Regards,

Anthony

[Sigurd Hellesvik]

Hi

I am talking to our developers on what the problem might be.
They have two questions for you:

Could you provide what version of the nRF52840DK? (number below the PCA10056 on the sticker)

How do you build the project?

Regards,
Sigurd Hellesvik

[Anthony Yuan]

Hi,

Could you provide what version of the nRF52840DK? (number below the PCA10056 on the sticker)

-- The sticker says: PCA10056 1.0.0 2018.43

How do you build the project?

-- I am using Visual Studio Code's nRF Connect Plugin to Pristine build default multiprotocol sample and flash DK. I will use default west commands to pristine build/flash DK again and let you know how it works.

Regards,

Anthony

[Anthony Yuan]

Hi,

I just tried using below west commands to build and flash DK1

west build -p -b nrf52840dk_nrf52840 -- -D OVERLAY_CONFIG=overlay-mtd-sed.conf -D CONFIG_LOCK=y

west flash --erase

And then do Homekit provision:

nrfjprog -f nrf52 --sectorerase ./provisioned_xxx-xx-xxx.hex

And then pairing with Apple Home App again.

The average current is still > 2mA.

Regards,

Anthony Yuan