NRFutil DFU over BLE works the first time and then fails with error code 13

[Bart Nathan]

Hi Everyone, 

I'm using nrfutil in an arm cortex a8 running Debian 9 with kernel 4.14.49. The processor is connected to a NRF52 dongle through USB. I'm trying to flash (using DFU) a new application to a remote NRF52 chip through BLE. I can successfully send the application firmware one time, but if I try to repeat the operation I get an error. To get rid of the error I need to disconnect and re-connect the USB (NRF52 Dongle), then I can send one new application successfully, and after that the error repeats itself.

The software versions:
nrfutils was installed from pip and its version 3.5.1
pc-ble-driver-py was compiled from source and its version 0.11.3
The firmware running in the NRF52 usb dongle is the connectivity firmware example from the SDK 15.0 for softdevice 132, (named ser_s132v3_usb_hci).

The error output that I get (for the second attempt to send th DFU over BLE) is:

user@system:~$ nrfutil -v -v dfu ble -ic NRF52 -pkg ~/nrfutils/bt_data_logger_mr_pickle.zip -p /dev/ttyACM0 -n "Pickle 15791"
2018-09-20 11:43:57,826 Shared library: /usr/local/lib/python2.7/dist-packages/pc_ble_driver_py-0.11.3-py2.7.egg/pc_ble_driver_py/lib/linux/x86_32/libpc_ble_driver_shared_sd_api_v3.so
2018-09-20 11:43:57,830 Swig module name: pc_ble_driver_sd_api_v3
2018-09-20 11:43:58,279 Using connectivity board at serial port: /dev/ttyACM0
2018-09-20 11:43:58,319 Sending Application image.
Traceback (most recent call last):
File "/usr/local/bin/nrfutil", line 11, in <module>
sys.exit(cli())
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 722, in __call__
return self.main(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 697, in main
rv = self.invoke(ctx)
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 535, in invoke
return callback(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/nordicsemi/__main__.py", line 840, in ble
dfu.dfu_send_images()
File "/usr/local/lib/python2.7/dist-packages/nordicsemi/dfu/dfu.py", line 141, in dfu_send_images
self._dfu_send_image(self.manifest.application)
File "/usr/local/lib/python2.7/dist-packages/nordicsemi/dfu/dfu.py", line 97, in _dfu_send_image
self.dfu_transport.open()
File "/usr/local/lib/python2.7/dist-packages/nordicsemi/dfu/dfu_transport_ble.py", line 450, in open
self.dfu_adapter.open()
File "/usr/local/lib/python2.7/dist-packages/nordicsemi/dfu/dfu_transport_ble.py", line 106, in open
self.adapter.driver.open()
File "/usr/local/lib/python2.7/dist-packages/pc_ble_driver_py-0.11.3-py2.7.egg/pc_ble_driver_py/ble_driver.py", line 127, in wrapper
raise NordicSemiException('Failed to {}. Error code: {}'.format(wrapped.__name__, err_code))
pc_ble_driver_py.exceptions.NordicSemiException: Failed to open. Error code: 13

Any idea of where this error might come from? I tried to reset the NRF52 dongle, but it does not solve the problem. Any help would be very appreciated. 

[Vidar Berg]

Hi, 

It sounds like it may be related to issue posted in this thread: https://devzone.nordicsemi.com/f/nordic-q-a/29059/pc-ble-driver-py-failed-to-open. As a test, could you try to pull the CTS line low and see if it helps?   

[Bart Nathan]

Hi Vidar, 

First of all, thanks a lot for your help. The thread you are pointing to is using a PCA10000 dongle, with an NRF51 chip and a Segger programmer on the same board. I am using the NRF52 PCA10059 dongle, which does not have a Segger programmer chip on it. Therefore, the programming is done through USB DFU. Meaning that I do not have a UART interface, where I could pull the CTS line low. 

What else could we try? Thanks again for the help.

[Vidar Berg]

Thanks for the clarification, I assumed you were using the nRF52832 dongle which has a OB Segger chip. This is clearly a different problem. I'll check internally whether this is a known problem or not and if there is a solution for it. I'll let you know as soon as I know more. 

[Vidar Berg]

Assuming you built the connectivity FW yourself, please try to use the pre-compiled ones and see if you experience the same behavior: https://github.com/NordicSemiconductor/pc-ble-driver/blob/release/v2.3.2/hex/sd_api_v3/connectivity_1.2.3_usb_with_s132_3.1.hex (or connectivity_1.2.3_usb_dfu_pkg.zip if you use nrfutil for USB DFU).  

[Bart Nathan]

You asume correctly, I am building the connectivity FW myself. I tried the .zip file (using nrfutil for USB DFU), as you recommended, but the results are the same. I can successfully update the remote NRF52 the first time, but after that the following attempts fail with the same error as before. 

What else could we check?

Thanks for the help. 

[Vidar Berg]

Unfortunately, I have not be able to reproduce the problem yet making troubleshooting a bit hard. I used the 52840 dongle with Ubuntu running in VirtualBox. I will try the same on a raspberry pi since I don't have anything with A8 that I can use for test.

Some follow up questions:

1. Is the serial port listed in /dev/ after the first attempt. I think it should be based on the error code, so this is just to confirm this assumption. 

2. Is the failing consistent. I.e., does it always fail on the 2nd attempt, or have you seen cases where it fails after 3 attempt,etc?

3. Is it possible to check if the port is kept open after the first attempt?  

4. What version of boost did you use for building the driver?