FRDM-KW38 Configuring pin voltage

[Dharani_Palanisamy]

Hello Everyone,

I have started working with #FRDM-KW38. I use another board X for ECG Data acquisition. I need to connect Board X and FRDM-KW38 through @SPI and also supply board X a 5V and 3.3V from FRDM-KW38. 

My questions now, 

1. I am thinking of using 5V source from J3 pin#5 and 3.3V from J3 pin#4. Is this correct or possible?

2. How to configure J3 pin#4 from 1.8V to 3.3V ?

Disclaimer : I am a student and a newbee to this world of NXP. 
Thank you,
Dharani. 

[EduardoZamora · Accepted solution]

Hello @Dharani_Palanisamy

Hope you are doing well.

You should be able to get 5V from J3-5 as this pin should be connected to USB Host 5V.

To achieve 3V on J3-4, you would need to make some hardware modifications to your board, this may involve changing DCDC configuration (Power configuration) from Buck mode (default) to Bypass mode. For more information on this, please refer to the FRDM-KW38 Schematics included in the Hardware design files that can be downloaded from the FRDM-KW38 webpage, Design Resources section:

Regards,
Eduardo.