USB not working anymore on xCORE-200 eXplorerKIT

Technical discussions around xCORE processors (e.g. General Purpose (L/G), xCORE-USB, xCORE-Analog, xCORE-XA).
User avatar
lbogdan
New User
Posts: 2
Joined: Fri Sep 23, 2016 8:52 am

USB not working anymore on xCORE-200 eXplorerKIT

Postby lbogdan » Fri Sep 23, 2016 9:34 am

Hey guys,

I've been playing with an xCORE-200 eXplorerKIT and the USB Audio Class 2.0 Software for the last couple of weeks. Everything was working just fine until yesterday, when, out of the blue, after a recompile / xrun, the USB stopped working - the USB audio device is no longer recognized, when I insert it into the computer nothing happens. I've also tried with some simpler USB examples (which worked before), with USB both on tile[0] and tile[1] - nothing worked. :-(

Did anyone have this problem before? Is there a chance this is a non-hardware issue? Is there any debugging I can do?

Thanks,
Bogdan
User avatar
johned
XCore Addict
Posts: 185
Joined: Tue Mar 26, 2013 12:10 pm

Postby johned » Mon Sep 26, 2016 9:35 am

Hi Bogdan,

I can't speak for OSX or Linux but one possibility under Windows is a driver issue.
I find that when developing USB applications, sometimes Windows driver configurations get confused. The best solution is to use usbdevview (http://www.nirsoft.net/utils/usb_devices_view.html) to uninstall any existing drivers.
If you sort drivers in VID order you can see all of the XMOS devices together (VID = 20b1).
You will need to run usbdevview as administrator.

I hope this helps.
All the best,
John
User avatar
lbogdan
New User
Posts: 2
Joined: Fri Sep 23, 2016 8:52 am

Postby lbogdan » Mon Sep 26, 2016 11:07 am

Hey John,

Thank you for your response!

I've tried with both USBDeview and USB Device Tree Viewer (http://www.uwe-sieber.de/usbtreeview_e.html); I get no "USB device inserted" sound, though, so they're not much help. Also tried to plug it into several computers / OSes, with no luck.

Unfortunately, the only explanation I can find is a physical damage of the internal USB PHY. (something like https://www.xcore.com/forum/viewtopic.p ... 760#p22760) But I asked anyway, maybe I'm missing something and I won't need to buy another board.

Any other suggestions are more than welcome!

Thanks,
Bogdan
User avatar
larry
Respected Member
Posts: 275
Joined: Fri Mar 12, 2010 6:03 pm

Postby larry » Mon Sep 26, 2016 5:21 pm

Do you see any activity on D+/D- before as it's going through attach signalling and transitioning from full speed to high speed?

If you don't have an oscilloscope, do you have a USB analyser? With that you could also look for signs of life such as packets upstream or device signalling.
expertsleepers
Member
Posts: 12
Joined: Thu Mar 03, 2016 4:28 pm

Postby expertsleepers » Fri Nov 04, 2016 1:29 pm

I'm inclined to think physical damage to the xCORE-200 is likely. I've had the same thing happen, and I'm beginning to think the XC-200 is not terribly robust.

Worse, the reference design has no ESD or other protection. I would like to see XMOS post some recommendations about how to best protect these parts.
User avatar
mon2
XCore Legend
Posts: 1849
Joined: Thu Jun 10, 2010 11:43 am

Postby mon2 » Fri Nov 04, 2016 1:50 pm

The xCORE-200 eXplorerKit does offer onboard ESD protection - at least shown in the schematics. If D7 is stuffed then there is onboard ESD protection. However, in our opinion, there are better suited parts to protect the USB interface.

Image

Better options are:

SOCAY p/n ULC0524P

http://www.socay.com/upfile/201407020248027678.pdf
* suitable for USB 2.0 and USB 3.1 Gen 1 (aka USB 3.0)
* ultra low capacitance

$0.042 USD in 3k T&R qty (MOQ), Shenzhen, CN.

(same footprint) as Littlefuse p/n SP3012-04

http://www.mouser.com/ProductDetail/Lit ... 52bg%3d%3d

To further enhance the designs, insert some current limit circuit or device into Vbus. Polymer fuses (< $ 0.20 USD from Digikey) are common here but they do derate after numerous triggers. A more robust and faster reaction time but more expensive can be found in solid state USB load switches which offer reverse current protection and also selectable current triggers. Review the many public Arduino designs for ideas on USB current protection using polymer SMD fuses.

Example of a suitable polymer fuse for USB projects:

http://www.digikey.com/product-detail/e ... ND/4156209
Last edited by mon2 on Fri Nov 04, 2016 1:50 pm, edited 1 time in total.
expertsleepers
Member
Posts: 12
Joined: Thu Mar 03, 2016 4:28 pm

Postby expertsleepers » Fri Nov 04, 2016 1:54 pm

Thanks.

In my case I was using the xCORE-200 Multichannel Audio Platform, which doesn't have ESD protection.

I've used that TI part myself (I think I copied it from an old XMOS design). I'll look into your recommendations - many thanks for replying.
expertsleepers
Member
Posts: 12
Joined: Thu Mar 03, 2016 4:28 pm

Postby expertsleepers » Fri Nov 04, 2016 2:19 pm

The ULC0524P you recommended is a 4-channel device. Two of these would be D+ and D-. Do you also suggest using one channel for the VBUS line (at the connector end)?
User avatar
mon2
XCore Legend
Posts: 1849
Joined: Thu Jun 10, 2010 11:43 am

Postby mon2 » Fri Nov 04, 2016 4:19 pm

Some general comments:

1) Review the SOCAY website to find a suitable USB 2.0 fit for ESD and/or EMI filter options. They have higher capacitance, lower cost options with fewer channels of protection for USB 2.0 HS / LS support. As noted, the costs will be lower but for us, the small delta in cost is usually worth the extra expense so we can continue to use the same SKU on our pending USB 3.x designs.

http://www.socay.com

2) DO NOT single source any such parts. Always be on the search of at least one other vendor who can offer the same footprint for same fit, form and function. This way, you can always start with a local supplier (higher premium on cost due to lower volume buys) and then migrate to the T&R MOQ quantities of typically 3k pieces per T&R. Suspecting the USB 2.0 device will be under $ 0.04 USD each.

Most recent Socay contact (met with them a few weeks back in HK): Daisy
socay017@socay.com <socay017@socay.com>

Email them any details and spec and they can cross to their p/n with datasheet for confirmation.

3) To kick up your design, consider the use of the EMI filters for USB 2.0 use. Socay has many models to choose from and shipping from Shenzhen is quite simple and relatively low cost. We have sourced some EMI filters (common mode chokes), direct from another manufacturer for our pending USB 3.x designs and that is Kingcore (Taiwan).

Last contact we have on file is: Rex Chen
King Core Electronics Inc.
O.Phone: +886-3-4698855#201
e-mail: rex@mail.kingcore.com.tw

They offer true drop in and spec equivalents to the major common mode choke manufacturers at a much reduced BOM cost for USB 2.0 and USB 3.x.

FYI: P/N WCM-2012-900T ; for USB 2.0 High Speed use
Comparing to Inpaq MCM2012B900GBE

KC p/n.WCM-2012-900T
Price USD0.04/pc FOB Taiwan
SPQ=3000pcs/reel

You will have to review the landed cost of the same to your location to see if this is a fit.

4) Try to consolidate your BOM to limit the number of parts to be placed on the PCB during assembly. The assembly fees are usually higher than the cost of the part you are placing. For this reason, we always tweak the design for manufacturing including the use of resistor networks (1206) vs. single resistors (0402). From our last review, 0402 SMD parts are the lowest cost for despike (ie. 0.1uf, etc.) - Samsung appears to be the winner most of the time we price exercise. Be very cautious of the capacitance vs. voltage of operation vs. package size. There is a relationship between these 3 values and how they will impact the true capacitance for your end project.

Here is another post of this discussion that started it all:

https://www.maximintegrated.com/en/app- ... vp/id/5527
* must read for any circuit designer

5) Avoid HASL plating on your PCB unless building by hand is a no-care. The landing pads will not be as flat (coplanar) as can be for the finer parts. ENIG finish is recommended with gold plating. ROHS and conflict of minerals compliance is a must. Halogen free PCB is recommended and is the norm for the larger OEM accounts we supply.

6) Rather than continue to ramble - post back if you need any help on other parts, PCB guidance, etc. and will try to assist where we can. Have been to Asia many times and feel comfortable with most of the suppliers we have used over the years. Not all are equal as some are just some and mirrors - promise one quality and deliver another.

Who is online

Users browsing this forum: No registered users and 1 guest