UART log working with nrf52840dk/nrf52811 but not with nrf52840dk/nrf52840

[Luca Cocchetti]

Hello, I've completed nRF Connect SDK Fundamentals Certificate of Completion but I've noticed a little problem with printk and logging.

When I use build configuration with board nrf52840dk/nrf52811 the output show the results I expected, when I use nrf52840dk/nrf52840 the output is not produced.

The problem is produced from blinky to all the excercises further.

With RTT the output is shown correctly.

DevBoard nrf52840dk with MCU PCA10056 2.0.1 2020.53 683522331, ncs v.2.9.1, west v. 1.2.0, toolchain 2.9.1

The major issue became with bluetooth course because nrf52811 generate overflow with RAM.

Any suggestion on how to procede?

Thank you

Luca

[Vidar Berg]

Hello Luca,

I can't think of anything that could explain why logging over UART only works when the 'nrf52811' emulation target is selected. Just to make sure the UART pin assignment hasn't been changed inadvertently (modified in SDK tree or through a devicetree overlay), please compare the generated zephyr.dts file between the two builds to confirm that the pinout remains the same.

UART pin assigments:

You may also want to verify that the uart0 node is enabled:

Best regards,

Vidar