ADC reading from coin-battery to Putty

[Zachary16]

Hi everyone, 

I'm currently trying to program my nRF52DK (nrf52382) to show it's battery voltage on the PuTTY emulator.

In order to run/simulate on the PuTTY emulator, I have connected my nRF52DK to my laptop via USB.

However connecting via USB will provide power to the development kit which overwrites the power supplied from coin-battery, hence during my simulation, the ADC reading was read from the USB instead of the coin-battery.

Is there a way I can "disable" the power from USB or connect other GPIO pin to read ADC from the coin-battery.

*In my programming, i have configured the saadc channel to 'saadc_input_vdd'.

*programming was written as a single-ended saadc mode.

*no sampling of ADC is needed for now. 

 

Thanks!

[Karl Ylvisaker]

Hello,

Is there a way I can "disable" the power from USB or connect other GPIO pin to read ADC from the coin-battery.

Unfortunately, no - the nRF52 DK will be supplied from the voltage source with the source that has the highest voltage, which will be the USB whenever it is connected and supplying power.
Later DK's - like the nRF52840 DK - has a power supply source switch, but the nRF52 DK does not.

If you wish to measure the voltage of the battery you will therefore need to disconnect the USB, and then perform the sampling. If you wish to see these measurements on your serial monitor you could either do so by a hardware connection where you connect the boards UART pins to an adapter that's connected to your PC so that you may see the logs directly, or you can use another nRF DK as a BLE adapter to receive the logs over a BLE connection.

Best regards,
Karl

[Zachary16]

Hi Karl

Thank you for the reply! Much appreciated!

[Karl Ylvisaker]

No problem at all, I am happy to help!

Please do not hesitate to open another ticket if you should encounter any issues or questions in the future.

Good luck with your development!

Best regards,
Karl