Cannot boot after power off/on

[rastik]

I'm trying to program Sparkfun nRF52832 board using SWD (via nRF52 DK). I've erased original bootloader/softdevice/app and programmed S132 and my app. The app works, but only until power is disconnected and connected again.Then the blue led (pin 7) stays on and the app does not execute. If I program the app again the chip works fine, again until power off/on. Actually, it is enough to read the chip with nRFgo Studio and the led goes off and the app executes correctly. When in working state, I can even reset the chip with a button and it still works. Is there any difference between start after power on and after reset button is pressed? How can I get board to work after power on? Thank for help and advice.

[rastik]

I've found the problem, even though I don't understand the reason yet. The line that causes the problem is:

NRF_POWER->DCDCEN = 1;

DCDC is enabled at the beginning of execution and even though it works on DK, it causes problems on the Sparkfun board.

[Wojtek]

You are using sparkfun nrf52832 breakout board? It does not have parts needed for dc/dc powering (inductor). That is the reason why dc/dc (and whole module) does not work i think.

[rastik]

Thank you for pointing that out, I didn't check that in the specs.