nRF52840-QIAA USB CDC ACM example not working in custom board.

[Hinal Tailor]

Hello

I have uploaded USB CDC ACM example code in my custom board of nRF52840. I didn't get Vcc on D+ pin and cannot detect USB. I have also check soldering side and resistance between (D+, D-) to ground. I was debug code line by line but I didn't get any error.

please suggest some solution to detect USB.

Bast Regards,

Hinal Tailor

[Turbo J]

Check NRF_POWER->USBREGSTATUS register. The USB pins are powered by the VBUS pin.

[Hinal Tailor]

Hiii

Thank you for your response.

I would like to inform you that I didn't power nRF52840 from VBUS. I am powering SoC from external supply 2.5V from buck converter to VDD.

Best regards,

Hinal Tailor

[Turbo J]

That would leave the USb pins unpowered. These require the 5Volts from VBUS.