# Connecting to D+ and D-

**URL:** https://discuss.blues.com/t/connecting-to-d-and-d/584
**Category:** Hardware
**Created:** [December 30, 2021, 10:42pm UTC](https://discuss.blues.com/t/connecting-to-d-and-d/584 "2021-12-30T22:42:19Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![Pat](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/pat/32/143_2.png) [@Pat](https://discuss.blues.com/u/Pat)
#### Post date: [December 30, 2021, 10:42pm UTC](https://discuss.blues.com/t/connecting-to-d-and-d/584/1 "2021-12-30T22:42:19Z")

</div>

Greeting Blues Team.

I am working on a custom PCB for Notecard.  
Do the lines coming from USB connector to USB\_DM and USB\_DP need 33 ohm resistors in line?  
If not needed…

Is this circuit all I need to cause a PC to enumerate the Notecard as a USB CDC device?

Thanks

 ![Screenshot 2021-12-30 173210](https://us1.discourse-cdn.com/flex020/uploads/blues/original/1X/d7fc0fe6d436103650632792a553204ef3aab409.jpeg)

---

<div class="post-metadata">

### Author: ![John\_Wiedey](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/john_wiedey/32/125_2.png) [@John\_Wiedey](https://discuss.blues.com/u/John_Wiedey)
#### Post date: [December 30, 2021, 11:09pm UTC](https://discuss.blues.com/t/connecting-to-d-and-d/584/2 "2021-12-30T23:09:16Z")

</div>

Hi Pat,  
Yes - your USB VCC, D-, D+, and GND signals are all connected correctly between your USB connector and Notecard M.2 connector to allow Notecard to enumerate and provide a USB Serial interface. You do not need additional inline resistors.  
We recommend that you copy the USB shield grounding scheme from our reference Notecarrier designs at [GitHub - blues/note-hardware](https://github.com/blues/note-hardware)  
For instance, here is the relevant section for our Notecarrier-AL schematic:

 ![image](https://us1.discourse-cdn.com/flex020/uploads/blues/original/1X/997e9cca9075bed012ae8ed3e2d7752e9bab462d.png)  
Best Regards,  
John Wiedey  
Blues Wireless

---

<div class="post-metadata">

### Author: ![Pat](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/pat/32/143_2.png) [@Pat](https://discuss.blues.com/u/Pat)
#### Post date: [December 30, 2021, 11:19pm UTC](https://discuss.blues.com/t/connecting-to-d-and-d/584/3 "2021-12-30T23:19:18Z")

</div>

Thank you John.  
I’ll look more at the references.