Programming external/custom NRF52832 board using NRF52-DK

Hi All,

We are trying to flash our custom NRF52832 board using NRF52-DK+nrf studio. With the same setup that's suggested by image description

However, from the nrf studio, we can never see the external board (nrf5x programming menu item is greyed out).

We've also tried to using a j-link/jtag but were still unable to see the external board.

We've tested the power supply on the custom board while connecting it to the DK board (2.8v, required 3.3v). Don't know if this could be the problem?

Thanks a lot!