VSUB CDC communication on nrf52840 holyiot

[Anmol]

Can i commuicate over USB CDC on  holyiot nrf52480 by giving Vbus(5v) , D+,D- , gnd from pc. and get output on VDD or do i have to also supply voltage on VDD(3V) ?
I wanted to connect my custom holyiot nRF52840 via USB. while doing so i supplied 5v to VDDH and D+ ,D- ground connection using PC the system was not recognized. after checking on Multi meter VDDH had 5V but VDD(3V) had no voltage. I supplied 3v via on-board voltage regulator to VDD pin then only i was able toc ommuicate over USB CDC with the holyiot.

[awneil]

Anmol said:

holyiot

You mean this: http://www.holyiot.com/ ?

That's an independent 3rd party - nothing to do with Nordic.

For specific questions about their products, you need to contact them!

https://devzone.nordicsemi.com/f/nordic-q-a/51583/asking-how-to-load-firmware-on-holyiot-nrf52832-dongle/207132#207132

[Anmol]

Can you tell for nRF52480 chip do i need to supply vdd with 3v and VBUS 5v , D+ , D- , ground to commuincate over USB CDC. or can it be done without supplying 3v to VDD pin

[awneil]

What does the Product Specification tell you?

[Anmol]

Power supply mode 

they tell not to connect.

[awneil]

Really?

I read:

"As a consequence, both VBUS and either VDDH or VDD supplies are required for USB peripheral operation."

https://infocenter.nordicsemi.com/topic/ps_nrf52840/power.html?cp=3_0_0_4_2_1#power_usb_supply 

But you still need to confirm with holyiot how their hardware design impacts this.

[Anmol]

Thank you awneil.
i appreciate your help.

VDD and VDDH are shorted on the module holyiot.

question is solved