Nordic nRF52-DK disconnects from computer when uploading compiled BIN files from mbed

[Keith Hammock]

I have a Nordic nRF52-DK that I am using to create and run programs written using the mbed compiler. I have followed the instructions outlined here on the mbed website( os.mbed.com/.../) for uploading the current firmware also provided on that website. Now, whenever I try to upload a compiled BIN file that I have written and compiled using the mbed compiler, the board disconnects from my computer and immediately reconnects, whilst having no compiled BIN file on the board. Also, at random points while the board is connected and I am doing things not related to the board, like traversing the internet, the board will also disconnect and reconnect.

[Jørgen Holmefjord]

Hi,

It is normal that the board disconnects and reconnects when you are flashing using "Drag-and-drop" method. Are you sure that the application is working?

The random disconnects sounds like an issue with the cable or power to the board. Do you have any serial output from your application that can indicate if the chip is reset in these cases?

Did you flash the mbed firmware to the interface chip on the nRF52-DK, or are you using the default Segger J-Link OB firmware?

Best regards,

Jørgen

[Keith Hammock]

I then uploaded my compiled code again and pressed the RESET button, but it does the same thing as when I press the RESET button immediately after connecting the board. I have also noticed a file titled "fail.txt" that appears on the board's root directory after it disconnects and reconnects from my laptop at random tines while I am typing. It does not appear when uploading the compiled code. The contents of the file read "timeout".