NRF9160 custom board uart communication

Question

Hi,

I'm trying to build the Serial LTE Modem in my nrf9160 SIP custom board to communicate the STM32 MCU with the nrf9160 using AT Commands via uart.

My physical connections between STM32 MCU and nrf9160 are:

UART RX --> P0-05

UART TX --> P0-06

UART RTS --> P0-14

UART CTS --> P0-15

This is my "nrf9160dk_nrf9160_ns.overlay":

/ {

chosen {

ncs,slm-uart = &uart2;

};

&uart0 {

status = "disabled";

hw-flow-control;

};

&uart2 {

compatible = "nordic,nrf-uarte";

current-speed = <115200>;

status = "okay";

hw-flow-control;

pinctrl-0 = <&uart2_default_alt>;

pinctrl-1 = <&uart2_sleep_alt>;

pinctrl-names = "default", "sleep";

};

&i2c2 {

status = "disabled";

};

&pinctrl {

uart2_default_alt: uart2_default_alt {

group1 {

psels = <NRF_PSEL(UART_RX, 0, 5)>;

bias-pull-up;

};

group2 {

psels = <NRF_PSEL(UART_TX, 0, 6)>,

<NRF_PSEL(UART_RTS, 0, 14)>,

<NRF_PSEL(UART_CTS, 0, 15)>;

};

uart2_sleep_alt: uart2_sleep_alt {

group1 {

psels = <NRF_PSEL(UART_TX, 0, 6)>,

<NRF_PSEL(UART_RX, 0, 5)>,

<NRF_PSEL(UART_RTS, 0, 14)>,

<NRF_PSEL(UART_CTS, 0, 15)>;

low-power-enable;

};

And here is my "nrf9160dk_nrf9160_ns.conf":

# Configuration file for nRF9160DK.

# This file is merged with prj.conf in the application folder, and options

# set here will take precedence if they are present in both files.

# Use UART_0 (when working with PC terminal)

# unmask the following config

# CONFIG_UART_0_NRF_HW_ASYNC_TIMER=2

# CONFIG_UART_0_NRF_HW_ASYNC=y

# CONFIG_SLM_POWER_PIN=6

# CONFIG_SLM_INDICATE_PIN=2

# Use UART_2 (when working with external MCU)

# unmask the following config

CONFIG_UART_2_NRF_HW_ASYNC_TIMER=2

CONFIG_UART_2_NRF_HW_ASYNC=y

CONFIG_SLM_POWER_PIN=31

CONFIG_SLM_INDICATE_PIN=30

Here is my prj.conf:

# General config

CONFIG_LOG=y

CONFIG_LOG_DEFAULT_LEVEL=3

CONFIG_STACK_SENTINEL=y

CONFIG_PICOLIBC_IO_FLOAT=y

CONFIG_RING_BUFFER=y

CONFIG_REBOOT=y

CONFIG_EVENTFD=y

# Segger RTT

CONFIG_USE_SEGGER_RTT=n

# Where console messages (printk) are output.

# By itself, SLM does not output any.

CONFIG_RTT_CONSOLE=n

CONFIG_UART_CONSOLE=y

# Where SLM logs are output.

CONFIG_LOG_BACKEND_RTT=n

CONFIG_LOG_BACKEND_UART=n

# Network

CONFIG_NETWORKING=y

CONFIG_NET_SOCKETS=y

CONFIG_NET_NATIVE=n

CONFIG_NET_IPV4=y

CONFIG_NET_IPV6=y

# Modem library

CONFIG_NRF_MODEM_LIB=y

CONFIG_AT_CMD_CUSTOM=y

# Align the max FD entry to NRF_MODEM_MAX_SOCKET_COUNT(8)

CONFIG_POSIX_MAX_FDS=8

# Handle modem fault

CONFIG_NRF_MODEM_LIB_ON_FAULT_APPLICATION_SPECIFIC=y

# Use GPIO

CONFIG_GPIO=y

CONFIG_GPIO_NRFX=y

# UART interface

CONFIG_SERIAL=y

CONFIG_UART_USE_RUNTIME_CONFIGURE=y

CONFIG_UART_ASYNC_API=y

CONFIG_NRFX_TIMER2=n

# Stacks and heaps

CONFIG_MAIN_STACK_SIZE=4096

CONFIG_HEAP_MEM_POOL_SIZE=16384

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=4096

CONFIG_AT_MONITOR_HEAP_SIZE=4096

# Device power management

CONFIG_PM_DEVICE=y

# FOTA

CONFIG_HTTP_PARSER_URL=y

CONFIG_FOTA_DOWNLOAD=y

CONFIG_FOTA_DOWNLOAD_PROGRESS_EVT=y

CONFIG_DFU_TARGET=y

CONFIG_DOWNLOAD_CLIENT=y

CONFIG_DOWNLOAD_CLIENT_STACK_SIZE=4096

CONFIG_DOWNLOAD_CLIENT_MAX_FILENAME_SIZE=2048

CONFIG_BOOTLOADER_MCUBOOT=y

CONFIG_IMG_MANAGER=y

# FLASH

CONFIG_FLASH=y

CONFIG_FLASH_PAGE_LAYOUT=y

CONFIG_FLASH_MAP=y

CONFIG_STREAM_FLASH=y

CONFIG_MPU_ALLOW_FLASH_WRITE=y

CONFIG_IMG_ERASE_PROGRESSIVELY=y

# Settings

CONFIG_SETTINGS=y

CONFIG_SETTINGS_NVS=y

CONFIG_NVS=y

# nRF Cloud

CONFIG_NRF_CLOUD_IPV6=n

CONFIG_NRF_CLOUD_MQTT=y

CONFIG_NRF_CLOUD_FOTA=n

CONFIG_NRF_CLOUD_AGNSS=y

CONFIG_NRF_CLOUD_AGNSS_FILTERED=n

CONFIG_NRF_CLOUD_PGPS=n

CONFIG_NRF_CLOUD_LOCATION=y

CONFIG_NRF_CLOUD_LOG_LEVEL_INF=y

CONFIG_NRF_CLOUD_GPS_LOG_LEVEL_INF=y

CONFIG_NRF_CLOUD_CLIENT_ID_SRC_INTERNAL_UUID=y

CONFIG_NRF_CLOUD_WIFI_LOCATION_ENCODE_OPT_MAC_RSSI=y

CONFIG_DATE_TIME=y

CONFIG_MODEM_INFO=y

CONFIG_MODEM_INFO_ADD_DATE_TIME=n

# UUID and JWT

CONFIG_MODEM_JWT=y

# MQTT client

#CONFIG_MQTT_KEEPALIVE=60

CONFIG_MQTT_CLEAN_SESSION=y

# AT command helper libraries

CONFIG_AT_CMD_PARSER=y

CONFIG_AT_MONITOR=y

#

# SLM-specific configurations

#

CONFIG_SLM_CUSTOMER_VERSION=""

CONFIG_SLM_EXTERNAL_XTAL=n

# debug options

#CONFIG_ASSERT=y

#CONFIG_LOG_BUFFER_SIZE=16384

#CONFIG_SLM_LOG_LEVEL_DBG=y

#CONFIG_LOG_PRINTK=n

#CONFIG_LOG_MODE_IMMEDIATE=y

# For using external GNSS antenna

#CONFIG_MODEM_ANTENNA=y

#CONFIG_MODEM_ANTENNA_GNSS_EXTERNAL=y

I have a lot of errors when building the application:

Kconfig tree parse failed: Could not open 'c:/ncs/v2.7.0-rc2/zephyr/boards/nordic/nrf9160dk/[email protected]_nrf9160_defconfig' (ENOENT: No such file or directory). Check that the $srctree environment variable (set to 'C:/ncs/v2.7.0-rc2/zephyr') is set correctly.

NRF_MODEM_LIB has direct dependencies SOC_SERIES_NRF91X && TRUSTED_EXECUTION_NONSECURE with value n, but is currently being y-selected by the following symbols:
- MODEM_INFO , with value y, direct dependencies y (value: y)
- MODEM_JWT , with value y, direct dependencies y (value: y)

CONFIG_UART_2_NRF_HW_ASYNC_TIMER couldn't be set. Missing dependencies:
UART_2_NRF_HW_ASYNC && HAS_HW_NRF_UARTE2

CONFIG_UART_2_NRF_HW_ASYNC was assigned the value y, but got the value n. Missing dependencies:
HAS_HW_NRF_UARTE2 && HAS_HW_NRF_PPI || HAS_HW_NRF_DPPIC && HAS_HW_NRF_UARTE2

I don't know what to do.. so, please, could you help me?

thanks!