Cannot use nPM2100, module_pmic_adc: Error: ADC reading failed (-5)

[Ziyao Zhou]

Hi,

I have a brand new npm2100 EK, after connect it and update the firmware, I cannot access the PMIC. The serial said :

module_pmic_adc: Error: ADC reading failed (-5)
15:42:47.157	module_pmic: No response from PMIC.
15:42:47.648	module_pmic_adc: Error: ADC reading failed (-5)
15:42:47.656	module_pmic: No response from PMIC.
15:42:48.148	module_pmic_adc: Error: ADC reading failed (-5)
15:42:48.156	module_pmic: No response from PMIC.

 Thank you!

[Edvin]

Hello,

Apparently, the nPM controller (the nRF53 running the FW) is powered through the USB port, and works fine. Otherwise, there wouldn't be any logs. The logs indicate failed I2C communication with the PMIC.

So it looks like th PMIC itself is not powered.To power the PMIC you need to either:

1: Attach a suitable battery using a battery add-on

2: Switch VBAT SEL into the VEXT position

Can you try either of the two, and let me know the outcome?

Best regards,

Edvin

[Ziyao Zhou]

When I switch it to VEXT, everything works correctly. Could you please clarify whether using VEXT or VBAT makes any difference when measuring the power consumption from the battery?

In VEXT mode, is the PMIC powered by USB, meaning that the measured power consumption would not represent the actual battery-powered operation?

[Edvin]

That is correct. In VEXT, you are powering the nPM via an external source, and it's current is not caluclated into the usage. While in VBAT, the current consumption of the nPM is also taken into consideration.

Best regards,

Edvin