nrf9160 MQTT example

[Dominik Windhab]

Hi!

I just saw the MQTT example that has been merged in the master branch and tried to run it on my DK (NB-IoT). Without changing anything in the code or configuration the execution leads to the following output in the console appears:

***** BUS FAULT *****
Precise data bus error
BFAR Address: 0x4002a514
***** Hardware exception *****
Current thread ID = 0x2000031c
Faulting instruction address = 0x6604
Fatal fault in essential thread! Spinning...

I used the latest tags of the releases of zephyr, etc. and only copied mqtt_simple from master branch. Are there any hints or tips how I can make the example work?

[shibshab]

Build and program the samples/nrf9160/secure_boot/ example first, then it should work.

This is needed since the SPU peripheral needs to be configured with a "NON SECURE" area, in which the MQTT example will reside.

The secure_boot sample performs this configuration.

[Dominik Windhab]

Hi! Thanks for the answer. There is something very strange going on.

So I am able to compile and flash secure_boot, at_client, asset_tracker, and the NTP example. Everything seems to work. Serial output looks ok.

(...)

Secure Boot: SPU: set SRAM region 30 as Non-Secure
Secure Boot: SPU: set SRAM region 31 as Non-Secure
Secure Boot: configure peripherals
Secure Boot: MSP_NS 200265f0
Secure Boot: prepare to jump to Non-Secure image
***** Booting Zephyr OS v1.13.99-ncs2 *****
The AT host sample started

(...)

Now opening and compiling the mqtt_simple example from the master branch.

After build and run the output in segger studio is:

(...)

Preparing target for download
Executing script TargetInterface.resetAndStop()
Reset: Halt core after reset via DEMCR.VC_CORERESET.
Reset: Reset device via AIRCR.SYSRESETREQ.
Downloading ‘zephyr.elf’ to J-Link
Programming 83.3 KB of addresses 00000000 — 00014d37
Programming 0.4 KB of addresses 00014d38 — 00014edb
J-Link: Flash download: Bank 0 @ 0x00000000: 1 range affected (16384 bytes)
J-Link: Flash download: Total time needed: 0.570s (Prepare: 0.042s, Compare: 0.041s, Erase: 0.357s, Program: 0.120s, Verify: 0.000s, Restore: 0.007s)
Download successful

Console output:

Secure Boot: SPU: set SRAM region 30 as Non-Secure
Secure Boot: SPU: set SRAM region 31 as Non-Secure
Secure Boot: configure peripherals
Secure Boot: MSP_NS 200265f0
Secure Boot: prepare to jump to Non-Secure image
***** Booting Zephyr OS v1.13.99-ncs2 *****
The AT host sample started
***** BUS FAULT *****
Precise data bus error
BFAR Address: 0x4002a514
***** Hardware exception *****
Current thread ID = 0x2000031c
Faulting instruction address = 0x6f74
Fatal fault in essential thread! Spinning...

Reset and power cycle leads to the same result. Immediate output is always "Bus Fault".

Now I tried to reprogram the at_client. But it seems like flashing another application is not possible. The output is the following:

(...)
Preparing target for download
Executing script TargetInterface.resetAndStop()
Reset: Halt core after reset via DEMCR.VC_CORERESET.
Reset: Reset device via AIRCR.SYSRESETREQ.
Downloading ‘zephyr.elf’ to J-Link
Programming 78.3 KB of addresses 00040000 — 0005397b
Programming 0.4 KB of addresses 0005397c — 00053b23
J-Link: Flash download: Bank 0 @ 0x00000000: Skipped. Contents already match
Download successful

The only thing I can do is re-flashing the secure_boot sample. After that, the device starts to run the at_client

It seems like there is a problem when flashing the mqtt_client sample.

Is anybody experiencing similar problems?

[robmilne]

Hi Martin,

I followed the 7 steps above but cannot flash because of this error:

FileNotFoundError: [Errno 2] No such file or directory: 'nrfjprog': 'nrfjprog'

I ran pip3 install --user pynrfjprog and retried but it made no difference.  Any suggestions?

-rob

[Martin Lesund]

Hi Rob,

You are missing the nRF command Line Tools.

Please download it and it should work.

[robmilne]

Same result after untar of that archive into my /opt/SEGGER/JLink directory.  Is there a variable that I can 'export' so that ninja can find nrfjprog?

[Martin Lesund]

Hi Rob,

You need to add nrfjprog to PATH (set the path in Linux), so your terminal can find the program

[robmilne]

OK, I exported the location so that nrfjprog is accessible but I get this error now...

rob@rob-VirtualBox:~/dev/ncs/nrf/samples/nrf9160/mqtt_simple/build$ west -v flash --skip-rebuild
ZEPHYR_BASE=/home/rob/dev/ncs/zephyr (origin: manifest file /home/rob/dev/ncs/nrf/west.yml)
Using runner: nrfjprog
nrfjprog --ids
Flashing file: /home/rob/dev/ncs/nrf/samples/nrf9160/mqtt_simple/build/zephyr/zephyr.hex
nrfjprog --program /home/rob/dev/ncs/nrf/samples/nrf9160/mqtt_simple/build/zephyr/zephyr.hex -f NRF91 --snr 960011468 --sectorerase
ERROR: JLinkARM DLL reported an error. Try again. If error condition
ERROR: persists, run the same command again with argument --log, contact Nordic
ERROR: Semiconductor and provide the generated log.log file to them.
ERROR: command exited with status 33: nrfjprog --program /home/rob/dev/ncs/nrf/samples/nrf9160/mqtt_simple/build/zephyr/zephyr.hex -f NRF91 --snr 960011468 --sectorerase
Traceback (most recent call last):
File "/home/rob/dev/ncs/.west/west/src/west/main.py", line 505, in main
args.handler(args, unknown)
File "/home/rob/dev/ncs/.west/west/src/west/main.py", line 326, in ext_command_handler
command.run(*west_parser.parse_known_args(argv))
File "/home/rob/dev/ncs/.west/west/src/west/commands/command.py", line 85, in run
self.do_run(args, unknown)
File "/home/rob/dev/ncs/zephyr/scripts/west_commands/flash.py", line 32, in do_run
'ZEPHYR_BOARD_FLASH_RUNNER')
File "/home/rob/dev/ncs/zephyr/scripts/west_commands/run_common.py", line 246, in do_run_common
runner.run(command_name)
File "/home/rob/dev/ncs/zephyr/scripts/west_commands/runners/core.py", line 407, in run
self.do_run(command, **kwargs)
File "/home/rob/dev/ncs/zephyr/scripts/west_commands/runners/nrfjprog.py", line 128, in do_run
self.check_call(cmd)
File "/home/rob/dev/ncs/zephyr/scripts/west_commands/runners/core.py", line 466, in check_call
subprocess.check_call(cmd)
File "/usr/lib/python3.6/subprocess.py", line 291, in check_call
raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['nrfjprog', '--program', '/home/rob/dev/ncs/nrf/samples/nrf9160/mqtt_simple/build/zephyr/zephyr.hex', '-f', 'NRF91', '--snr', '960011468', '--sectorerase']' returned non-zero exit status 33.

..sorry for being a pain.