External battery supply issue to DK

[Roger]

Hi,

I'm supplying a DK with an external battery source plugged into J6 (Li-Po) and the nRF power source switch set to VDD. When I flash the chip with one of the Openthread client examples, the DK operates normally when the board is supplied by an external battery source rated at 4.2V fully charged.

Now, when I flash the board with the s140 SoftDevice (using the nRF5_SDK_14.0.0_3bcc1f7 file repository) and run the ble_app_uart_c example with the board also supplied by the 4.2V external battery source (with the USB cable now disconnected), the board does not function. I see the onboard led's flash and barely visible. Only when I use the USB cable as a power source, then does the board operate normally and the program runs as expected.

For an external battery source, does this have something to do with a setting in registries in one of the libraries?

[Roger]

Hi Martin,

Yes, of course, I checked all those things. The battery is a NiMH battery rated at 3.6V and fully charged at 4.2V. I measured 3V over VDD and 5V over the 5v pin. As I mentioned earlier, the board works fine with an external battery source when I run the Thread client example. Irrespective whether I set the switch to VDD or Li-Po, the board still works with an external battery source. I'm thinking that the problem I'm encountering is perhaps something to do with software when I use the SoftDevice? Is it possible to emulate this test on one of your DK?