NRF 52840 DK Battery Level Reading

[Radio]

Hi All,

I am trying to implement a battery level reading app using NRF52840 DK. It seems I am receiving a timeout from saadc.

In order to run on the Lithium battery, should we set the switch to VDD or Li-Po?

Thanks!!

[Radio]

Hi Stian,

Thanks for the reply. In the nrF52840 DK, there is a switch to select "nRF Only" | "Default".

Currently set to "Default". May I know:

1. What is the purpose of this switch?

2. If it only powers the nRF chip? If so from where does it get power? 

Thanks!

[Stian Røed Hafskjold]

1. It disconnects the nRF52 GPIOs and SWD interface from the rest of the DK, so you don't get any leakage current when measuring on the nRF chip.
2. The nRF chip gets its power from the USB, LiPo or the external power header. The problem is that these domains power the rest of the chip

You can power the nRF directly from the external power header, if you set SW10 (VEXT->nRF) to ON. The problem is that this only works in normal voltage mode. For high voltage mode there is no way to power only the chip.

[Radio]

Hi Stian,

Thank you very much for the information.