Firmware blocked until RTT connects

[scottc19]

My firmware is blocked on custom board until RTT connects: Code hits and blocks on a printf.  This doesnt happen when using an NRF5340, but does with NRF5280.  Just trying to figure out if this is expected and if there is a work around to have RTT enabled but not block execution.  If it matters I am using USB and BLE and both are enabled prior to printf.  If I use the debugger it looks like it faults when hitting the printf.

using these:

CONFIG_CONSOLE=y

CONFIG_STDOUT_CONSOLE=y

CONFIG_RTT_CONSOLE=y

CONFIG_USE_SEGGER_RTT=y

CONFIG_UART_CONSOLE=n

I tried this but didnt seem to help:

CONFIG_SEGGER_RTT_MODE_NO_BLOCK_SKIP=y

Also note that eventually the firmware does start eventually after a long day 30+sec if RTT is not started.

[Menon]

Hello,

Which SDK version are you using? Also, are you testing this on a DK or a custom board?

Kind regards,
Abhijith

[scottc19]

nrf Connect SDK 3.1.0 and custom board as mentioned

[Menon]

Hello,

What happens when you use the log backend with Zephyr logging over RTT instead of the console? Do you still experience the same issue? See CONFIG_LOG_BACKEND_RTT

Kind regards,

Abhijith

[scottc19]

Issue turned out to be:

#no crystal

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y

adding this line resolved the problem, not sure why the default is to have the system want a 32k crystal?  The default seems like it should be changed though for the nrf connect sdk.