USB error on dongle

[nix64bit]

I am using Linux (various breeds and hardware) and the nRF52840 Dongle. When I first plugged the dongle in it worked as expected

Then this

this is the output from dmesg (green light flashes a few times on the dongle)

[ 3392.595088] usb usb1-port4: attempt power cycle
[ 3394.023442] usb usb1-port4: Cannot enable. Maybe the USB cable is bad?
[ 3394.999016] usb usb1-port4: Cannot enable. Maybe the USB cable is bad?
[ 3394.999038] usb usb1-port4: unable to enumerate USB device

Any advice?

Peter

[Einar Thorsrud]

Hi,

Have you reprogrammed the dongle firmware? If so, it might be that the new firmware does not enable USB at all, so you have to press the reset button to start the bootloader in USB DFU mode.

[nix64bit]

I did reprogram the dongle, I also tried to reset using the button S1 which doesn't do anything probably because it has no power? Are there instructions to power directly from the pins? I see there are 3.3V/GND pins, all I can think of next is to power directly and then reset? 

[Einar Thorsrud]

Hi Peter,

Then this is expected as the new firmware probably does not enable the USB. The reset button is not the SW1 switch, but rather a sideways switch close by (please see the illustration). Pushing this should make the dongle enter USB DFU mode, and should allow the computer to enumerate it. Can you double check?

[nix64bit]

Thank you, problem solved, sorry to have wasted your time without reading the docs properly 

[Einar Thorsrud]

No problem. Glad to hear you got it working