NRF52840 DK - Programming external custom board at 3.3V

[bpolito8]

Hi,

I’m looking to program an external device that runs on 3.3V with my NRF52840 DK (v3.0.1), and I’m looking to verify that this is possible. I know that the DK runs at 3.0V.

If I would like to achieve this through the P19/Debug OUT Connector, should I bridge SB19 and leave SB47 open? I am planning to power the device separately from the DK. Please let me know if I am on the right track with this approach, thank you!

[SwRa]

Hello,

VIO_REF is the reference for GPIO/SWD I/O voltage. SB19 connects that external VIO_REF into the DK’s I/O domain so the debugger and GPIOs follow that voltage (within the allowed range). SB47 on nRF52‑series DKs is used when you want the DK to supply power out through P19; when SB47 is shorted, you must not also power the external board separately. See here: https://docs.nordicsemi.com/bundle/ug_nrf52840_dk/page/UG/dk/ext_programming_support_P19.html 

Regards,

Swathy

[ign0]

Hi, sorry for interrupting here, but, if my custom board has 1v8 power on my nRF52833 and im using nRF52833-DK how can i program/debug the boards?