The development board I am using is FRDM-KW41Z.
Is there any API related to reading the power supply voltage in the SDK package?
Are you looking to use a specific protocol ? Are you looking to use Thread?
You can check for example in the reed example the API called BOARD_GetBatteryLevel ? Does that work for you ?
I am using a Thread Stack.
Does the API need to set the power mode to a specific mode?
I saw in the manual that the DCDC module needs to configure the registers to connect the DCDC module to the ADC channel, so do I need to write the registers separately?