boards/thingy52: use RTT console as default

External JLink is required to program the board, so the console via RTT
is available anyway. It is much more convenient to use than soldering the
P4 connector and working with an external UART converter.

Author: raiden00pl

Documentation/platforms/arm/nrf52/boards/thingy52/index.rst

@@ -29,13 +29,27 @@ Battery monitoring                 No
 Serial Console
 ==============
 
+At default serial console is available with Segger RTT driver.
+For access to the RTT console use this commands::
+
+  JLinkGDBServer -if SWD -device stm32h743zi -speed 16000
+  sudo socat -d -d PTY,link=/dev/ttyRTT0,raw,ignoreeof TCP:127.0.0.1:19021,reuseaddr
+  minicom -D /dev/ttyRTT0
+
+An alternative option is to use the P4 connector and connect an external UART converter:
+
 ===== ========== ==========
 Pin   Signal     Notes
 ===== ========== ==========
-P0.02 UART TX    P4 header
-P0.03 UART RX    P4 header
+P0.02 UART0 TX   P4 header
+P0.03 UART0 RX   P4 header
 ===== ========== ==========
 
+For this you need to select the following options in your configuration::
+
+  CONFIG_NRF52_UART0=y
+  CONFIG_UART0_SERIAL_CONSOLE=y
+
 Configurations
 ==============
 
@@ -49,7 +63,7 @@ Where <subdir> is one of the following:
 nsh
 ----
 
-Basic NuttShell configuration (console enabled in UART0, exposed via P4 header, at 115200 bps).
+Basic NuttShell configuration (console enabled on Segger RTT channel).
 
 Flash & Debug
 =============

boards/arm/nrf52/thingy52/configs/nsh/defconfig

@@ -19,7 +19,6 @@ CONFIG_ARCH_STDARG_H=y
 CONFIG_BOARD_LOOPSPERMSEC=5500
 CONFIG_INIT_ENTRYPOINT="nsh_main"
 CONFIG_MM_REGIONS=2
-CONFIG_NRF52_UART0=y
 CONFIG_NSH_ARCHINIT=y
 CONFIG_NSH_FILEIOSIZE=512
 CONFIG_NSH_LINELEN=64
@@ -30,9 +29,10 @@ CONFIG_RAM_START=0x20000000
 CONFIG_RAW_BINARY=y
 CONFIG_RR_INTERVAL=200
 CONFIG_SCHED_WAITPID=y
+CONFIG_SERIAL_RTT0=y
 CONFIG_START_DAY=26
 CONFIG_START_MONTH=3
 CONFIG_SYMTAB_ORDEREDBYNAME=y
+CONFIG_SYSLOG_RTT=y
 CONFIG_SYSTEM_NSH=y
 CONFIG_TASK_NAME_SIZE=0
-CONFIG_UART0_SERIAL_CONSOLE=y