nRF52810 board will not start on its own. It needs the RTT Viewer to be connected, then it will start and run.

[epolicar]

nRF52810 board will not start on its own. It needs the RTT Viewer to be connected, then it will start and run. It has run on its own before with this configuration:

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y

CONFIG_CLOCK_CONTROL_NRF_K32SRC_XTAL=y

CONFIG_SEGGER_RTT_MODE_NO_BLOCK_SKIP=n

Does anyone have any idea? I have struggled with this for a week now.

PS:

My schematic follows the reference schematics in the datasheet, which means the RESET line is floating. I am convinced this is not an issue because I have another board from Holyiot (beacon) with also floating reset. This board starts and run on its own just fine using the same firmware (pin assignments re-mapped, of course).

Regards,

[JONATHAN LL]

This issue is common to see when the 32kHz crystal is missing, the RTT viewer start ste device in a debug mode so then it simulates it internally. 

Doas all SW not work or just yours? 

Have you tested something else?

Regards,
Jonathan

[epolicar]

All my SW does not work.

[epolicar]

Also, RTT viewer is not in debug mode.

[epolicar]

Hi Jonathan, I would like to follow up on this

[JONATHAN LL]

How does the board get power?

Can you share schematics?

epolicar said:

All my SW does not work.

Have you tested som basic samples ?

Regards,
Jonathan

[epolicar]

JONATHAN LL said:

Have you tested som basic samples ?

Yes, I did. 

I made a bare metal code that blinks LED. This code starts up on itw own upon power up. Could the problem be in Zephyr start up code and configuration?