During experimenting the Thingy:91 lost its USB-DFU bootloader, how to get it back?

[Gwen Stouthuysen]

I got a Thingy:91 back from a student who managed to kill the USB-DFU bootloader.

When connecting a USB cable the host doesn't recognize anything connected.

I tried to program the thingy91_nrf52_usb_uart_bridge_2020-10-30_5522ca2b.hex file to the nRF52840 MCU and this brought a difference: now W10 sees something on the other side of the USB cable but still no recognition that helps me.

Any advice on how to solve this?

[Didrik Rokhaug]

Hi,

 

I tried to program the thingy91_nrf52_usb_uart_bridge_2020-10-30_5522ca2b.hex file to the nRF52840 MCU and this brought a difference: now W10 sees something on the other side of the USB cable but still no recognition that helps me.

 What does Windows see?

 From what folder did you take the .hex file?

I got a Thingy:91 back from a student who managed to kill the USB-DFU bootloader.

 Do you know how?

Is it the nRF52840 that is the problem, or the nRF9160?

Anyway, the easiest solution, is if you have an external programmer (such as an nRF9160 DK, or an nRF52XXX DK), and then program the nRF52840 and/or the nRF9160 that way.

Best regards,

Didrik

[Gwen Stouthuysen]

I got the FW from the nordic website: https://www.nordicsemi.com/Software-and-tools/Prototyping-platforms/Nordic-Thingy-91/Download#infotabs

Windows simply doesn't recognize the device and resets the connection, he keeps on doing this till you unplug.

How the student managed this I don't know, he told me he deleted something that gave errors in the Windows system.

If you tell me which files should be programmed to which processor in the Thingy:91 I can try this out.

I'm using the nRF9160-DK debug out connector.

What I miss in these files from the nordic website is the bootloader: there was no bootloader anymore on the nRF52840.

[Gwen Stouthuysen]

I just tried it again.

Installed: 

• thingy91_at_client_2020-10-30_5522ca2b.hex on the nRF9160
• thingy91_nrf52_usb_uart_bridge_2020-10-30_5522ca2b.hex

The files I took from the img_app_bl folder in the zip file.

My W10 computer tries to set up a serial interface but fails and tries again.

On Linux no ttyACM socket is coming up. (the nRF9160-DK does bring up 3)

Drivers are missing he claims.

I use the nRF Connect programmer. (v3.6.1)

Gwen

[Didrik Rokhaug]

The images in the img_app_bl folder has the bootloader (MCUBoot), the secure patrition manager (SPM, only for the nRF9160) and the application. These images must be used with an external programmer (as you did).

The images in the img_fota_dfu_bin and img_fota_dfu_hex folders only has the SPM and the application. These images can be used for DFU and/or FOTA. The .hex files in the Programmer app, the .bin files for FOTA or the command line with mcumgr.

When you programmed the Thingy, did you change the position of the "SWD SELECT" switch to the correct position depending on which MCU you were programming?

Also, could you try to program thingy91_nrf52_connectivity_bridge_2020-10-30_5522ca2b.hex to the nRF52840?

[Gwen Stouthuysen]

I always check which processor is mentioned in the programmers log file, those switches are difficult to read and see the position.

Loading the proposed file indeed made a difference: now the ttyACM sockets come up and the Thingy:91 is installed in W10. (two interfaces, I suppose one for each processor)

Thanks, I hope this info can help others.