Unbrick Nano33 IOT via ARM CMSIS-DAP compliant debugger

[torchddv]

The tititular board suddenly quit responding following an upload when tweaking code. The power light comes on, but Windows no longer recognizes that the board has been connected to the USB port. The program does not run when the board is powered up either. The code works on another identical board, so I'm not sure what went wrong, but assume it's bricked somehow.

I am trying to unbrick mine following the suggestion in multiple closed threads to use the CMSIS-DAP Compliant SWD Debugger. I also have a 3x2 pogo adapter and a break-out board (SWD (2x5 1.27mm) Cable Breakout Board : ID 2743

I am unclear on what pin connects where, but assume it follows the conventional pinout as screenprinted on the breakout board. I selected the Atmel EDBG programmer and then "Burn Bootloader", resulting in the following error message:

Open On-Chip Debugger 0.10.1+dev-gf0767a31 (2018-06-11-13:36) Licensed under GNU GPL v2 For bug reports, read http://openocd.org/doc/doxygen/bugs.html debug_level: 0 0 none separate adapter speed: 400 kHz cortex_m reset_config systresetreq in procedure 'init' in procedure 'ocd_bouncer'

Error while burning bootloader.


My OS is Windows 7 with SP1 and all updates. Device manager reports two new Human Interface Devices when the debugger is plugged in:
"HID-compliant device" and
"USB Input Device"
Both report "This Device is working properly" but no driver was installed or requested and no new serial ports created.

The LED is lit on the debugger, but there is no voltage at the Vref pin. The debugger LED blinks very briefly when attempting to write the bootloader, before the error message appears.

I have tried powering the Nano separately via a second USB cable. As before, the green power LED comes on, but no difference when attempting to write the bootloader.

I have also tried installing Microchip Studio, in the hopes that might provide any needed driver to interface with the debugger, but that had no effect either.

If anyone has successfully made this thing work in a Windows environment, I would appreciate your insight.

[UKHeliBob]

I cannot offer any help about using the programmer that you have but I have unbricked my Nano 33 IOT an number of times using an ESP32

See this topic Unbrick Nano 33 IoT - #14 by pert

[Juraj]

it doesn't need a port.
ensure right connection of the programmer

[torchddv]

I have verified that the POGO pins are physically in contact with the board. I am confused by the documentation on GIThub for the debugger, but I think the pinout of J1 follows the same designations as the breakout board.

I have wired things so that:

BOB Vref (pin 1) >> Nano +3.3v

BOB GND (pin 5) >> Nano GND

BOB SWIO (pin 2) >> Nano SWDIO

BOB CLK (pin 4) >> Nano SWCLK
    ___
BOB RST (pin 8) >> Nano RESETN

I do have another Nano 33 IOT that I could try as a programmer, but don't have an SD card module. If I can't get this to work then I guess the SD card route would have to be next.

(I'm not sure how to insert images, but the Nano pads are as identified in the image at:
https://europe1.discourse-cdn.com/arduino/original/4X/1/a/f/1af50cd45ad3c44e48e6dba9ec610827df68defc.jpeg)

[Juraj]

btw did you try double reset to activate the bootloader? the onboard LED should pulsate.

[torchddv]

Yes, I tried that soon after the thing quit responding. Nothing happens -- the light comes on when I plug in the USB cable and stays on no matter how many times or how fast I press the reset button.

That's why I think it's bricked. Well, that and Windows doesn't recognize when it's plugged in anymore.

This all started when I was updating the sketch (I was playing with the accelerometer values). It went through the upload procedure, followed by the Windows disconnect "bong" sound. But it never reconnected. There was no expected connection notification after the reset, the port disappeared from the Arduino Tools menu, Windows Device Manager no longer saw it either.

The light comes on, but nobody's home...