LPCOpen usb mass storage example detecting as UNKNOWN DEVICE lpc11u14

[lpcware]

Content originally posted in LPCWare by sarangkalbande on Wed Apr 24 21:10:46 MST 2013

Hi all,

I am working on lpc11u14.Recently I have tried LPCOpen USB Mass storage Examople but when I compile the code and trnsfer it in my MCU successfully.When I connect my device to PC,it detects the device as UNKNOWN DEVICE.what could be the problem as the examples given on LPCOpen is working one I think.

Please reply fast,if anyone has ever faced this problem

[lpcware]

Content originally posted in LPCWare by nikhil on Wed Jul 23 00:21:13 MST 2014
I connected my LPC1769 EA Board to my host and after flashing mass storage device.c file my host was able to detect the device properly.Later I was able to see "my usb memory device demonstrated"....can which part of the code flushes out this message????????

[lpcware]

Content originally posted in LPCWare by tuong on Thu May 02 01:01:14 MST 2013

Hi,

LPC11u14 is weak on memory, so the example has to fake Windows by declaring a big capacity than its real capacity. With the disk image located on RAM, we can control the file Windows reads but we cannot control where it gonna writes to, so I guess the fault is when we read/write at positions out of disk image scope.

With best regards,

[lpcware]

Content originally posted in LPCWare by sarangkalbande on Sun Apr 28 05:08:41 MST 2013

Hi Tuong,

Thank you very much.My issue is resolved it was issue with board reset.

Now I have one more query..as I am using mass storage example from lpcopen for lpc11u14,

when I connect my device to pc it detect the device and mount it properly having default readme.txt

file in it.But when I try to modify the file or try to copy new file in that it wont work..what could be the issue.

Basically I am not able to copy onto the RAM when the device is conncted to PC

[lpcware]

Content originally posted in LPCWare by tuong on Thu Apr 25 01:02:26 MST 2013

Hi,

I try v1.02 under LPCXpresso on LPCXpresso LPC11U14 Rev A and face no problem, it works out of box!

PC detects unknown device when it fails on enumerating that device. The enumeration process starts when there is 3.3V pulled up on D+, normal steps are: reset bus -> set address -> get device descriptor -> get configuration descriptor -> get string descriptors -> set configuration. So you may need to run debug and check:

   - If the firmware run normally, ex: start at startup ResetISR then jump to main() then not jump to hardfaultISR or similar error ISRs

   - If the 3.3V pulled up on D+ is controlled properly, this is done just after called USB_Init()

   - If these above steps are passed orderly

With best regards,