nRF52840 USB example crash

[ilia]

Hi. I've just received my nRF52840-PDK and now I am trying to run usb examples from SDK 13.1.0.

I have started with VisualGDB using arm-eabi toolchain and USB HID Generic example from the SDK. The project built and flashed without errors. But when I connect second USB I get SIGTRAP exception in reent.c on NVIC_Enable_IRQ() in core_cm4.h. Pretty the same as here. The solution in that thread was to change startup files, but don't know how to make it. So this is a question number 1.

I have also tried to flash precompiled .hex files from the SDK, but for every USB example none of my PCs could recognize this USB device. So maybe I need to install some drivers for HID examples?

Other options I have checked, without success:

• build with GNUARM toolchain from command line as well as from VisualGDB (in case of VisualGDB I had to select software FP instead of hardware, and disable softdevice);
• build with arm-eabi from VisualGBD using SDK 13.0.0 and 13.1.0.
• build projects from examples in IAR, not succeeded.

What do I need to do to get working USB on nRF52840?

[Hung Bui]

I'm sorry that it's a little bit busy here to test the VidualGDB project. But if you have issue with the precompiled hex I don't think it's about your project setting of start up file. HID device should work out of the box. I would suggest to acquire another nRF52840 PDK for testing and replace your current board. If you want to compile and test an example, I would suggest to also try with gcc. But I don't think it would make any different compare to the pre-compiled hex.