nRF52840 development kit

[BAEE]

I am trying to connect to another type of board via the UART on the development kit.  However, there seems to be a voltage mismatch.  Are the nRF52840 development kit UART signals TTL level versus CMOS level?

[Øyvind]

Hello, 

What voltage level are the boards running? The nRF52840 Dev Kit has multiple power supplies [LINK], however, the UART itself is powered internally by the nRF52840 chip and follows GPIO levels [LINK]. 

Kind regards,
Øyvind

[BAEE]

Thank you for the feedback.