LPC11U35 and custom class

lpcware · ‎06-15-2016

Content originally posted in LPCWare by fjarnjak on Thu May 16 02:30:44 MST 2013

Hello,

I am evaluating LPC11U35 for a simple DAQ device where PC application would use libusb to communicate to it using a simple protocol.

I have looked at:

http://www.lpcware.com/content/forum/nxpusblib-windows-winusb-driver-custom-class

but I have additional questions:

I see that LPC11U35 has ROM Based drivers for common communication classes and also USB core stack (enumeration, etc).

Is there a way to use ROM based USB stack for making sure USB protocol is handled correctly, and then registering simple endpoint handlers in bulk mode for IN and OUT where I do my custom protocol implementation?

Something similar to nxpUSBLib v0.98b Device Bandwidth Test code, but I do not want the device to appear as mass storage device while enumerating.

I have been looking at the new LPCOpen library 1.03 and it seems Device Bandwidth Test example is gone. Is this a limitation or? Since nxpUSBLib is retired...

Also, if this above is not possible I may use LPC1769 which I use for other projects, so if anyone has some experience doing this...

lpcware · ‎06-15-2016

Content originally posted in LPCWare by durgesh on Fri Jun 21 11:21:23 MST 2013

Did you check the traffic on bus? Is it really low-speed ?

This could be a bug in bandwidth test code (PC side). It assumes the speed based on the value returned by <strong>WinUsb_QueryDeviceInformation() </strong>routine. The code outputs the speed based on return value as below

0x3 - high speed, 0x2 - full speed, 0x1 - low speed.

Looks like MSFT update the document http://msdn.microsoft.com/en-us/library/windows/hardware/ff540290(v=vs.85).aspx saying "0x03 indicates high-speed or higher; 0x01 indicates full-speed or lower."

So PC tool should be updated with the change in WinUSB interface.

lpcware · ‎06-15-2016

Content originally posted in LPCWare by fjarnjak on Mon May 20 00:58:10 MST 2013

UPDATE:

I have ported device bandwidth test from nxpUSBLib to a new project.

PC USB test application from the device bandwidth test project correctly detects the device but only as "low speed" device, which is odd.

What needs to be changed?