nRF52840-DK External Power Supply + Onboard Debugger

[Aris]

Dear all,

For the purposes of the application that I am currently developing, I would like to operate the nRF52840-DK with an external power supply. From the DK's user guide I have understood that in order to supply the board with exactly 3.3V I could connect the external power supply to the "External Supply" connector.

To have both 3.3 V and 5 V, do I need to connect the Vin 3-5V pin with 5 V, too?

Is it possible to power both voltage channels (3.3 V & 5 V) externally and at the same time use the J2 on-board debugger?

I know that I could supply the 5 V only and let the DK handle the 3 V channel, but my application requires exactly 3.3V logic voltage level, not 3 V.

Thank you in advance for your help,

Aris.

[haakonsh]

Hmm, If you cut SB40 and 41 you should be able to power the nRF from P23 at 5V. If you've set the REGOUT0 register in UICR to 0x5 (3.3V) the nRF will operate at 3.3V.

Then you should be able to run the board from the USB connector as normal. Be warned though that the debugger might not like 3.3V on the pins that interface with the nRF device.