Modem error: 0x10, PC: 0x111df4 on booting nrf9160DK with mqtt_simple sample project

[oscar199]

Hello. I'm relatively new to zephyr and working with nrf's and I'm  experiencing a modem error when running the mqtt_simple sample project that I cant resolve.


Upon booting, i get the following result:

The only change I've made to the sample project is configuring mqtt variables and adding "CONFIG_LOG=y" in prj.conf
I think the first modem error is the root cause, because i also got this when trying to run a simple application (simply a printk() in main)

I've spent days trying to figure out what this means and how to fix it, but without luck. I was told that the nrf9160dk hardware is relatively old, so I suspected some version compatibility issues, however after revising the compatibility matrices online, I could not find any faults there.

I did find the nrf_errno.h in /nrfxlib/nrf_modem/, which says this error code means "no child process", however I couldnt figure out what that means and how to fix it. I've built this using the nrf connect sdk (version 2.1.99-dev1) which I installed manually by following the official guide. Before you ask why Im not using the nrf connect desktop app to automatically install - it is because we (3-4 students) got error messages we couldn't resolve when installing it automatically.

So my question is what is causing this error and how can I fix it?
I'll try to list all relevant specs, but please let me know if you need to know more.
OS: Ubuntu 20.4
nRF9160dk hardware version: 0.8.4 (PCA10090)
nrf connect sdk version: 2.1.99-dev1 (got same error running v2.1.0)
zephyr-sdk version: 0.14.1
modem firmware version: 1.3.2

Attaching the build output so you can get the full picture of the build system:

oscar@oscar-desktop:~/ncs/nrf/samples/nrf9160/mqtt_simple$ west build --board nrf9160dk_nrf9160_ns --pristine
-- west build: making build dir /home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/build pristine
-- west build: generating a build system
Loading Zephyr default modules (Zephyr base).
-- Application: /home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple
-- Found Python3: /usr/bin/python3.8 (found suitable exact version "3.8.10") found components: Interpreter 
-- Cache files will be written to: /home/oscar/.cache/zephyr
-- Zephyr version: 3.1.99 (/home/oscar/ncs/zephyr)
-- Found west (found suitable version "0.14.0", minimum required is "0.7.1")
-- Board: nrf9160dk_nrf9160_ns, Revision: 0.7.0
-- ZEPHYR_TOOLCHAIN_VARIANT not set, trying to locate Zephyr SDK
-- Found host-tools: zephyr 0.14.1 (/home/oscar/zephyr-sdk-0.14.1)
-- Found dtc: /home/oscar/zephyr-sdk-0.14.1/sysroots/x86_64-pokysdk-linux/usr/bin/dtc (found suitable version "1.6.0", minimum required is "1.4.6")
-- Found toolchain: zephyr 0.14.1 (/home/oscar/zephyr-sdk-0.14.1)
-- Found BOARD.dts: /home/oscar/ncs/zephyr/boards/arm/nrf9160dk_nrf9160/nrf9160dk_nrf9160_ns.dts
-- Generated zephyr.dts: /home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/build/zephyr/zephyr.dts
-- Generated devicetree_unfixed.h: /home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/build/zephyr/include/generated/devicetree_unfixed.h
-- Generated device_extern.h: /home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/build/zephyr/include/generated/device_extern.h
-- Including generated dts.cmake file: /home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/build/zephyr/dts.cmake
Parsing /home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/Kconfig
Loaded configuration '/home/oscar/ncs/zephyr/boards/arm/nrf9160dk_nrf9160/nrf9160dk_nrf9160_ns_defconfig'
Merged configuration '/home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/prj.conf'
Configuration saved to '/home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/build/zephyr/.config'
Kconfig header saved to '/home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/build/zephyr/include/generated/autoconf.h'
-- The C compiler identification is GNU 10.3.0
-- The CXX compiler identification is GNU 10.3.0
-- The ASM compiler identification is GNU
-- Found assembler: /home/oscar/zephyr-sdk-0.14.1/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc
Dropping partition 'nrf_modem_lib_trace' since its size is 0.
Dropping partition 'nonsecure_storage' since it is empty.
-- Configuring done
-- Generating done
-- Build files have been written to: /home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/build
-- west build: building application
[5/291] Preparing syscall dependency handling

[28/291] Generating include/generated/version.h
-- Zephyr version: 3.1.99 (/home/oscar/ncs/zephyr), build: v3.1.99-ncs1-10-gd4b8ac4db1ed
[58/291] Generating ../../tfm/CMakeCache.txt
-- The C compiler identification is GNU 10.3.0
-- The ASM compiler identification is GNU
-- Found assembler: /home/oscar/zephyr-sdk-0.14.1/arm-zephyr-eabi/bin/arm-zephyr-eabi-gcc
-- Found Python3: /usr/bin/python3.8 (found version "3.8.10") found components: Interpreter 
-- Found Python3: /usr/bin/python3.8 (found suitable exact version "3.8.10") found components: Interpreter 
-- Cache files will be written to: /home/oscar/.cache/zephyr
-- Configuring done
-- Generating done
-- Build files have been written to: /home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/build/tfm
[63/291] Performing build step for 'tfm'
[1/2] Re-running CMake...
-- Found Python3: /usr/bin/python3.8 (found version "3.8.10") found components: Interpreter 
-- Found Python3: /usr/bin/python3.8 (found suitable exact version "3.8.10") found components: Interpreter 
-- Cache files will be written to: /home/oscar/.cache/zephyr
-- Configuring done
-- Generating done
-- Build files have been written to: /home/oscar/ncs/nrf/samples/nrf9160/mqtt_simple/build/tfm
[169/169] Linking C static library secure_fw/libtfm_s_veneers.a
[65/291] Performing install step for 'tfm'
-- Install configuration: "MinSizeRel"
[279/291] Linking C executable zephyr/zephyr_pre0.elf

[283/291] Linking C executable zephyr/zephyr_pre1.elf

[289/291] Linking C executable zephyr/zephyr.elf
Memory region         Used Size  Region Size  %age Used
           FLASH:      106616 B       992 KB     10.50%
            SRAM:       21760 B     211736 B     10.28%
        IDT_LIST:          0 GB         2 KB      0.00%
[291/291] Generating zephyr/merged.hex

prj.conf:

#
# Copyright (c) 2020 Nordic Semiconductor ASA
#
# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
#

# Networking
CONFIG_NETWORKING=y
CONFIG_NET_NATIVE=n
CONFIG_NET_SOCKETS_OFFLOAD=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_POSIX_NAMES=y

# LTE link control
CONFIG_LTE_LINK_CONTROL=y
CONFIG_LTE_AUTO_INIT_AND_CONNECT=n

# Modem library
CONFIG_NRF_MODEM_LIB=y

# MQTT
CONFIG_MQTT_LIB=y
CONFIG_MQTT_LIB_TLS=n
CONFIG_MQTT_CLEAN_SESSION=y

# Application
# CONFIG_MQTT_PUB_TOPIC="my/publish/topic"
# CONFIG_MQTT_SUB_TOPIC="my/subscribe/topic"
# CONFIG_MQTT_CLIENT_ID="my-client-id"
# CONFIG_MQTT_BROKER_HOSTNAME="test.mosquitto.org"
# CONFIG_MQTT_BROKER_PORT=1883

# Button support
CONFIG_DK_LIBRARY=y

# Enable logging
CONFIG_LOG=y
CONFIG_MQTT_SIMPLE_LOG_LEVEL_DBG=y

# Memory
CONFIG_MAIN_STACK_SIZE=4096
CONFIG_HEAP_MEM_POOL_SIZE=2048

# NewLib C
CONFIG_NEWLIB_LIBC=y

# Shell support
CONFIG_SHELL=y

[Michal]

Hello,

Modem firmware version 1.3.x doesn't work on the engineering revisions of nRF9160.

I would highly suggest getting a newer DK revision, or at least downgrading the modem FW to 1.2.x

Best regards,

Michal

[oscar199]

Thank you for the quick reply! So my suspicion about compatibility issues with the old DK was correct after all. I'll try to get my hands on a newer DK. 

[Michal]

You're welcome and yes, your suspicions were correct.

Best regards,

Michal