Board hang when connect to PC with USB

[yama1010]

Hello all,

We check the custom board with nrf52840(BL654) , but it's hang PC and devices when connect the PC.

When the hang on my pc , we checked windows system event ID 153.

The after , it work normally.

If you know this problems , please tel me the some informations.

[Stian Røed Hafskjold]

Do you have some more information about the software you are running on the nRF52840. What do you mean by "hang PC"?

[yama1010]

Thank you for reply, we use the arduino firmware.

https://github.com/adafruit/Adafruit_nRF52_Arduino

About hang PC problems , keyboard , mouse and all process stop when bl654 custom board connect to USB connector.

But few minutes stop , all process start normally.

It often have this problem when restart the BL654.

[Stian Røed Hafskjold]

Hmm, that sounds weird. Are the keyboard and mouse connected to USB as well? Maybe there's a short circuit or something that causes the USB hub to fail and then the mouse and keyboard not to function?

For a design review please post the full PCB layout and schematics.

[yama1010]

About short circuit than USB mouser and keyboard, I checked some PC.But we checked same ploblems all windows 10 PC,but Mac don't have this ploblems.

We checked the sch by Laird Technologies support,and get the advice about don't assembly 4.7uF in USB VBUS.I think that it may have problem in software on Adafruit_nRF52_Arduino.

Thank you for your adveices.