We use nRF9160 on our own board.
The firmware "Serial lte modem" is installed on the chip with connection to an external MCU.
We had to change the SDK version to 1.9.1 from 1.8.
And here we got a problem that we do not receive a response to AT commands.
The new version of the SDK has new configuration files: nrf9160dk_nrf9160_ns.conf
We made changes to use an external MCU, but it did not help us in any way.
I am attaching the configuration "prj.conf" file:
# # Copyright (c) 2020 Nordic Semiconductor ASA # # SPDX-License-Identifier: LicenseRef-Nordic-5-Clause # # General config CONFIG_LOG=y CONFIG_LOG_DEFAULT_LEVEL=3 CONFIG_STACK_SENTINEL=y CONFIG_NEWLIB_LIBC=y CONFIG_NEWLIB_LIBC_FLOAT_PRINTF=y CONFIG_RING_BUFFER=y # Segger RTT CONFIG_USE_SEGGER_RTT=n CONFIG_RTT_CONSOLE=y CONFIG_UART_CONSOLE=y CONFIG_LOG_BACKEND_RTT=n CONFIG_LOG_BACKEND_UART=y # Network CONFIG_NETWORKING=y CONFIG_NET_SOCKETS=y CONFIG_NET_NATIVE=n # Modem library CONFIG_NRF_MODEM_LIB=y # Align the max FD entry to NRF_MODEM_MAX_SOCKET_COUNT(8) CONFIG_POSIX_MAX_FDS=8 # Enable below for modem trace #CONFIG_NRF_MODEM_LIB_TRACE_ENABLED=y # Use GPIO CONFIG_GPIO=y CONFIG_GPIO_NRFX=y # UART interface CONFIG_SERIAL=y CONFIG_UART_ASYNC_API=y CONFIG_NRFX_TIMER2=y # Stacks and heaps CONFIG_MAIN_STACK_SIZE=4096 CONFIG_HEAP_MEM_POOL_SIZE=16384 CONFIG_SYSTEM_WORKQUEUE_STACK_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_BOOTLOADER_MCUBOOT=y CONFIG_IMG_MANAGER=y # FLASH CONFIG_FLASH=y CONFIG_FLASH_PAGE_LAYOUT=y CONFIG_FLASH_MAP=y CONFIG_MPU_ALLOW_FLASH_WRITE=y CONFIG_IMG_ERASE_PROGRESSIVELY=y # Settings CONFIG_SETTINGS=y CONFIG_SETTINGS_FCB=y CONFIG_FCB=y # nRF Cloud CONFIG_CLOUD_API=y CONFIG_NRF_CLOUD_MQTT=y CONFIG_NRF_CLOUD_FOTA=n CONFIG_NRF_CLOUD_AGPS=y CONFIG_NRF_CLOUD_PGPS=y CONFIG_NRF_CLOUD_CELL_POS=y CONFIG_NRF_CLOUD_LOG_LEVEL_INF=y CONFIG_DATE_TIME=y CONFIG_MODEM_INFO=y CONFIG_MODEM_INFO_ADD_DATE_TIME=n CONFIG_AT_MONITOR=y CONFIG_MODEM_JWT=y # Use "nrf-<IMEI>" as the default device_id format # Use "<device_uuid>" as the device_id format by below #CONFIG_NRF_CLOUD_CLIENT_ID_SRC_INTERNAL_UUID=y # # SLM-specific configurations # CONFIG_SLM_CUSTOMIZED=n CONFIG_SLM_LOG_LEVEL_INF=y CONFIG_SLM_EXTERNAL_XTAL=n CONFIG_SLM_START_SLEEP=n #\nUse\nUART_0\n(when\nworking\nwith\nPC\nterminal) #CONFIG_UART_0_NRF_HW_ASYNC_TIMER=2 #\nUse\nUART_2\n(when\nworking\nwith\nexternal\nMCU) CONFIG_SLM_CONNECT_UART_2=y CONFIG_UART_2_NRF_HW_ASYNC_TIMER=2 #\nnRF\nCloud\nbased\nlocation\nservices CONFIG_SLM_AGPS=y CONFIG_SLM_PGPS=y CONFIG_SLM_CELL_POS=y CONFIG_SLM_LOG_LEVEL_DBG=y
And "nrf9160dk_nrf9160_ns.conf" file:
# # Copyright (c) 2021 Nordic Semiconductor ASA # # SPDX-License-Identifier: LicenseRef-Nordic-5-Clause # # 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_SLM_CONNECT_UART_0=y #CONFIG_UART_0_NRF_HW_ASYNC_TIMER=2 #CONFIG_UART_0_NRF_HW_ASYNC=y #CONFIG_SLM_INTERFACE_PIN=6 # Use UART_2 (when working with external MCU) # unmask the following config CONFIG_SLM_CONNECT_UART_2=y CONFIG_UART_2_NRF_HW_ASYNC_TIMER=2 CONFIG_UART_2_NRF_HW_ASYNC=y CONFIG_SLM_INTERFACE_PIN=31