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?

[ilia]

Hi @hungbui,

I've got another nRF52840 PDK with the same revision as my previous board, and USB HID Generic sample started to work. The device is correctly recognized as input device now. The only issue left - the device does not behave as stated in the SDK documentation. The LED2 which should show the USB library status is always OFF which means "USB library stopped". And my PC does not react to button click events from the board.