nrf52840 connect to usb on custom board

[area540]

Hi,

I am working on a custom nrf52840 board and am having trouble connecting to the usb interface on the chip.  After testing with the dev kit, the adafruit bootloader successfully launches when I connect to the nrf usb on the dev kit.  It also connects when I flash the dev kit with any of the usb examples in the SDK v16.  

I am able to successfully flash my custom board using the swd pins and an external battery, however when I connect my usb cable to the usb pins, the host computer does not recognize that I have plugged the board in despite the nrf receiving enough power.  To connect to usb, do I need to complete any other steps other than making sure to connect the usb ground to nrf ground, usb D+ to nrf pin AD6, usb D- to nrf pin AD4, and usb VDD to nrf pin AD2 and power the board?  

[ketiljo]

Can you post a schematic of your board please?

[area540]

I do have more in the schematic, but for testing I only have the SWD pins and USB pins connected at the moment.  The nrf is getting 3.3V from an external battery and the usb 5v is making it to the VBUS pin.

[area540]

Here are my physical board and the usb cable that I spliced to connect to my board.  USB Green (D+) goes to board yellow.  USB white (D-) goes to board orange.  USB black (GND) goes to board green.  USB red (VCC) goes to board red.

I checked the usb registers and it does not appear to recognize that it is receiving the usb 5v from the host computer. 

Thanks for any help!

[ketiljo]

If you're using a module, it should not be anything else but connecting VBUS; D+, D- and GND as you have done. All other parts should be on the module. What's the blue wire?

You need to power the board externally with max 3.6 V to VCC. It looks like VDD is connected to VDDH on the module so you can't power the module from VBUS.