Unable to migrate to RTT and now unable to restore UART console

[fon_brown]

I was trying to migrate to RTT on the nRF52840DK because my actual target has no UART. I changed prj.conf as shown:

CONFIG_CONSOLE=y

CONFIG_UART_CONSOLE=n

CONFIG_USE_SEGGER_RTT=y

CONFIG_RTT_CONSOLE=y

CONFIG_LOG=y

CONFIG_LOG_MODE_MINIMAL=y

And while the RTT viewer connects without error, there is no console output. The more troubling development is that when I tried to go back to UART output as a sanity check, I now have no console output there either. (prj.conf shown below)

CONFIG_CONSOLE=y

CONFIG_UART_CONSOLE=y

CONFIG_USE_SEGGER_RTT=y

CONFIG_RTT_CONSOLE=n

CONFIG_LOG=y

CONFIG_LOG_MODE_MINIMAL=y

The program is running, so there should be console output, and I have spent hours looking through your documentation and Q&A but everything I am told to do I have already done.

I know it is the Nordic way to have a dozen or so things that have to be just right in order for a certain feature to work. Can you please enumerate any and all configuration items that must be set properly, e.g. baud rates, handshake, memory addresses (for RTT) so I can go through them one by one and check to see where I have gone wrong?

Thanks.

[qwertynoon]

Hi. You have not provided enough information to make any conclusion

[fon_brown]

It was more a general request to provide a checklist that I or any other developer might consult when trying to debug console problems, but if you would like to help in this specific case, I am using SDK 2.1.2 With Zephyr RTOS, developing on Windows using nRF Connect on Visual Studio Code. The board is a nRF52840DK connected via USB. The code in nrf52840dk_nrf52840_defconfig is (I think) unchanged with:

# SPDX-License-Identifier: Apache-2.0

CONFIG_SOC_SERIES_NRF52X=y

CONFIG_SOC_NRF52840_QIAA=y

CONFIG_BOARD_NRF52840DK_NRF52840=y

# Enable MPU

CONFIG_ARM_MPU=y

# Enable hardware stack protection

CONFIG_HW_STACK_PROTECTION=y

# Enable RTT

CONFIG_USE_SEGGER_RTT=y

# enable GPIO

CONFIG_GPIO=y

# enable uart driver

CONFIG_SERIAL=y

# enable console

CONFIG_CONSOLE=y

CONFIG_UART_CONSOLE=y

# additional board options

CONFIG_GPIO_AS_PINRESET=y

CONFIG_PINCTRL=y

My prj.conf for this project is:

CONFIG_NCS_SAMPLES_DEFAULTS=y

CONFIG_CONSOLE=y

CONFIG_UART_CONSOLE=y

CONFIG_USE_SEGGER_RTT=y

CONFIG_RTT_CONSOLE=n

CONFIG_LOG=y

CONFIG_LOG_MODE_MINIMAL=y

CONFIG_BT=y

CONFIG_BT_MAX_CONN=1

CONFIG_BT_L2CAP_TX_BUF_COUNT=5

CONFIG_BT_PERIPHERAL=y

CONFIG_BT_DEVICE_NAME="RBI"

CONFIG_BT_DEVICE_APPEARANCE=962

CONFIG_HEAP_MEM_POOL_SIZE=2048

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048

# Enable the LBS service

CONFIG_BT_LBS=n

CONFIG_BT_LBS_POLL_BUTTON=n

CONFIG_DK_LIBRARY=y

#USB related configs

CONFIG_USB_DEVICE_STACK=y

CONFIG_USB_DEVICE_PRODUCT="Zephyr MSC sample"

#CONFIG_LOG=y

CONFIG_USB_DRIVER_LOG_LEVEL_ERR=y

CONFIG_USB_MASS_STORAGE=y

CONFIG_USB_DEVICE_LOG_LEVEL_ERR=y

CONFIG_USB_MASS_STORAGE_LOG_LEVEL_ERR=y

CONFIG_MAIN_STACK_SIZE=1536

#CONFIG_APP_MSC_STORAGE_RAM=y

CONFIG_APP_MSC_STORAGE_FLASH_FATFS=y

CONFIG_DISK_VOLUME_SIZE=0x800000

I did re-flash the S140 soft device version 7.3.0.

The nrf52840dk exposes 2 com ports and I have connected both to the nRF Terminal with baud 115200 8 bits no parity, no rts/cts.

I don't know if it is relevant, but my Kconfig for this project contains:

config USB_DEVICE_PID

    default USB_PID_MASS_SAMPLE

config APP_WIPE_STORAGE

    bool "Option to clear the flash area before mounting"

    help

      Use this to force an existing file system to be created.

choice

    prompt "Storage and file system type used by the application"

    default APP_MSC_STORAGE_NONE

    help

      Specify the type of storage and file system.

config APP_MSC_STORAGE_NONE

    bool "Use RAM disk as block device"

    imply DISK_DRIVER_RAM

config APP_MSC_STORAGE_RAM

    bool "Use RAM disk and FAT file system"

    imply DISK_DRIVER_RAM

    imply FILE_SYSTEM

    imply FAT_FILESYSTEM_ELM

config APP_MSC_STORAGE_FLASH_FATFS

    bool "Use FLASH disk and FAT file system"

    imply DISK_DRIVER_FLASH

    imply FILE_SYSTEM

    imply FAT_FILESYSTEM_ELM

config APP_MSC_STORAGE_FLASH_LITTLEFS

    bool "Use FLASH disk and LittleFS"

    imply DISK_DRIVER_FLASH

    imply FILE_SYSTEM

    imply FILE_SYSTEM_LITTLEFS

config APP_MSC_STORAGE_SDCARD

    bool "Use SDHC and FAT file system"

    imply DISK_DRIVER_SDMMC

    imply FILE_SYSTEM

    imply FAT_FILESYSTEM_ELM

endchoice

config DISK_RAM_VOLUME_SIZE

    default 32 if APP_MSC_STORAGE_NONE

config MASS_STORAGE_DISK_NAME

    default "NAND" if DISK_DRIVER_FLASH

    default "RAM" if DISK_DRIVER_RAM

    default "SD" if DISK_DRIVER_SDMMC

if DISK_DRIVER_FLASH

config FLASH_MAP

    default y

config FLASH_PAGE_LAYOUT

    default y

config DISK_FLASH_START

    default 0x0

config FLASH_LOG_LEVEL

    default 3

if NORDIC_QSPI_NOR

config NORDIC_QSPI_NOR_FLASH_LAYOUT_PAGE_SIZE

    default 4096

config DISK_FLASH_DEV_NAME

    default "MX25R64" if "$(dt_nodelabel_enabled,mx25r64)"

    default "GD25Q16" if "$(dt_nodelabel_enabled,gd25q16)"

config DISK_VOLUME_SIZE

    default 0x100000

config DISK_FLASH_MAX_RW_SIZE

    default 4096

config DISK_FLASH_ERASE_ALIGNMENT

    default 0x1000

config DISK_ERASE_BLOCK_SIZE

    default 0x1000

endif # NORDIC_QSPI_NOR

endif # DISK_DRIVER_FLASH

source "Kconfig.zephyr"

Is there anything else you would like to know?

[qwertynoon]

# Config logger
CONFIG_LOG=y
CONFIG_USE_SEGGER_RTT=y
CONFIG_LOG_BACKEND_RTT=y
CONFIG_LOG_DEFAULT_LEVEL=3

I use this conf to run RTT debuger