nRF52840 fails to connect over USB

RE: nRF52840 fails to connect over USB

Robert Lasater — Wed, 09 Sep 2020 14:35:12 GMT

Your 2nd answer with more details should now be marked as Verified.

RE: nRF52840 fails to connect over USB

Simonr — Wed, 09 Sep 2020 06:37:55 GMT

Hi Robert

Glad we were able to fix this. If you're satisfied with the answer, please verify the answer that helped you, so future DevZone users can find this reply more easily as well.

Best regards,

Simon

RE: nRF52840 fails to connect over USB

Robert Lasater — Tue, 08 Sep 2020 19:25:06 GMT

First, regret the delay in responding. The 3-day weekend came quicker than I expected.

I have good news: your fix worked.

For some reason, that board quit coming up, and I could not get it to present a new File Explorer window on my Linux PC. But to my surprise, this morning, the board came up without incident.

It has been a bit flakey in the past ...

Thanks for your help.

RE: nRF52840 fails to connect over USB

Robert Lasater — Thu, 03 Sep 2020 14:27:53 GMT

Thanks for clarifying your original answer. I'll give it a try and let you know what happens.

RE: nRF52840 fails to connect over USB

Simonr — Thu, 03 Sep 2020 05:46:42 GMT

Sorry, I forgot to include the link in my previous reply, I have edited the reply to include it now.

Your DK is connected to the computer by a USB connector, right? If you hold the IF BOOT/RESET button while powering the DK on, the device should go to bootloader mode and a bootloader window should appear similar to the picture below. If you drag the Interface MCU firmware file into this Bootloader folder (and nothing else, as that may damage the Interface MCU) the device should recover to its original state.

Best regards,

Simon

RE: nRF52840 fails to connect over USB

Robert Lasater — Wed, 02 Sep 2020 13:40:43 GMT

Sorry, I don't get your reply. Where is this .bin file? Where is the "driver folder of the DK"? I have no way to communicate or interact with the board.

RE: nRF52840 fails to connect over USB

Simonr — Wed, 02 Sep 2020 11:39:45 GMT

Hi Robert

It seems like you've accidentally set the board in Bootloader mode. You can recover it by flashing the Interface MCU firmware onto the debugger. Download the .bin file available here and drag and drop it into the driver folder of the DK. Wait for a while until LED 5 stops blinking and power off and on the board.

Best regards,

Simon