DFU - Failed to open transport backend

[c cook]

I followed the Nordic Tutorial located here. I'm using a PCA100028 Dev Board, MCP 3.9.0.6, and a Segger J-Link Plus. I'm using Keil uVision5, and used the pack installer method as described in the tutorial, to load the dual bank dfu example.

When I start the download using the test image (zip file) provided in the dfu folder, I get an "Failed to open transport backend" error.

Why? What's causing this error?

Also - How does one debug the bootloader code? The way the tutorial describes programing the nRF51, there is no way to enter debugging mode.

-Clint

[Hung Bui]

Hi Clint,

from the log you sent, it seems that the issue came from the PC side that the access to the log file location is blocked.

672;07:55:58.7567 [480112156][ScriptMethodCallThread] Service Discovery complete
673;07:56:04.3267 [480112156][ReadPacketQueueThread] Serial port read: 04-05-04-00-00-00-08
674;07:56:04.3267 [480112156][ReadPacketQueueThread] HCI event: BTLE_EVENT_DISCONNECTION_COMPLETE ConnectionHandle: 0x0000, Reason: BTLE_CONNECTION_TIMEOUT
675;07:56:04.3367 [480112156][ReadPacketQueueThread] Received LL Connection Termination Event, reason 08
676;07:56:04.3367 [480112156][ScriptThread] Lost connection to device. Reason: BTLE_CONNECTION_TIMEOUT
677;07:56:04.3467 [480112156][] SERVER: Received packet <HciEvent: eventCode=0x0A> - <HciEvent: eventCode=0x0A>
678;07:56:04.3467 [480112156][] SERVER: Received Link Loss
679;07:56:04.5067 [480112156][MainThread] HciH4Driver closed
680;07:56:04.5067 [480112156][] Error disconnecting: The port is closed.
681;07:56:07.3667 [480112156][MainThread] nrfjprog.dll 5.2.0.45231
682;07:56:07.3667 [480112156][MainThread] JLinkARM.dll 4.92
683;07:56:07.3767 [480112156][MainThread] 609302117 - 
684;07:56:07.3767 [480112156][MainThread] 480112156 - COM11
685;07:56:07.3767 [480112156][MainThread] 681121300 - COM15
686;07:56:07.4077 [480112156][MainThread] [07:56:07.407] [EXCEPTION] ('Could not initialize log file: %s', "Access to the path 'C:\\ProgramData\\Nordic Semiconductor\\MasterEmulator\\log.txt' is denied.")

Could you check if the location is blocked from normal access ( you can try to run MCP with administrator right) ? Do you have any issue when testing the MCP with normal use (not DFU) ?

You can also try to test the bootloader via a phone (iOS or MCP )

[Nate]

It looks like my issue was that I forgot to burn the bootloader. You can see the topic here. Thanks!