We have developed a small PCB that connects with some other HW. The integrated nRF52840 runs in HighVoltage-Mode and its required to set VDD to 3.0V. The question - how to do this - was discussed in several articles - I read them all and tried most codes - but nothing really runs. It is posible to set REGOUT0 in UICR 0x304 to 0x04. After the necessary Reset, this works in RUN-Mode outside IDE. In Debugger-Mode the Debugger shows an HW-error and stops. This happens also if I change the value during the Init-process in the program. As I agree with some comments, the much better way is to modify the setting for REGOUT0 during the building-process. There are some examples, I tried them too, but without success. Because some comment are over three years old, may be there were some changes. I hope, that there is a reliable solution.
Thanks in advance
Juergen